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Stellarium User Guide

1. D 2 3 2 ZoneRecordd 04__ E 0 5 Processing into a Panorama CONTENTS CONTENTS CONTENTS Tr vH ee eee F2 1 Altitude Azimuth Coordinate F 3 1 Distance F 3 3 Aneled ers E33 Notation r RAI F 3 4 Magnitude Scale CPP Hk Fa Rg gn ata ett ea ee OCT dp SPECT eee eee Tee Tee ee eee ee e Mode BO he Bere eee ae oe oh cae aie RT Me FERE d ee TTE H_Sky Guide CONTENTS CONTENTS L5 Scripta Messier Tour GNU Free Documentation License K Acknowledgements Bibliography Chapter 1 Introduction Stellarium is a software project that allows people to use their home computer as a virtual planetarium It will calculate the positions of the Sun and Moon planets and stars and draw how the sky would look to an observer depending on their location and the time It can also draw the constellations and simulate astronomical phenomena such as meteor showers and solar or lunar eclipses Stellarium may be used as an educational tool for teaching about the night sky as an observational aide for amateur astronomers wishing to plan a night s observing or simply as a curiosity it s fun Because of the high
2. fogtex 0 0 1 1 nb_decor_repeat 1 decor_alt_angle 40 decor angle shift 22 decor angle rotatez 0 ground angle shift 22 ground angle rotatez 45 fog alt angle 20 fog angle shift 3 draw ground first 1 Where name is the name that will appear in the landscape tab of the configuration window for this landscape type should be old style for the multiple image method nbsidetex is the number of side textures for the landscape tex0 tex lt nbsidetex 1 gt are the side texture file names These should exist inthe textures landscapes directory in PNG format nbside is the number of side textures 33 5 7 CUSTOMISING LANDSCAPES CHAPTER 5 ADVANCED USE sideO side lt nbside 1 gt are the descriptions of how the side textures should be arranged in the program Each description contains five fields separated by colon characters The first field is the ID of the texture e g tex0 the remaining fields are the coordinates used to place the texture in the scene groundtex is the name of the ground texture file ground is the description of the projection of the ground texture in the scene fogtex is the name of the texture file for fog in this landscape fog is the description of the projection of the fox texture in the scene nb_decor_repeat is the number of times to repeat the side textures in the 360 panorama decor_alt_angle is the vertical angular size of the textures i e how high they go into
3. planet comes from the Greek for wanderer The planets are like the Earth massive bodies that are in orbit around the Sun Until 2006 there was no formal definition of a planet leading to some confusion about the classification for some bodies widely regarded as being planets but which didn t seem to fit with the others In 2006 the International Astronomical Union defined a planet as a celestial body that within the Solar System a is in orbit around the Sun b has sufficient mass for its self gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium nearly round shape and c has cleared the neighbourhood around its orbit or within another system 1 is in orbit around a star or stellar remnants ii has a mass below the limiting mass for thermonuclear fusion of deuterium and iii is above the minimum mass size requirement for planetary status in the Solar System Moving from the Sun outwards the major planets are Mercury Venus Earth Mars Jupiter Saturn Uranus and Neptune Since the formal defintion of a planet in 2006 Pluto has been relagated to having the status of dwarf planet along with bodies such as Ceres and Eris See figure G 4 G 4 1 Terrestrial Planets The planets closest to the sun are called collectively the terrestrial planets The terrestrial planets are Mercury Venus Earth and Mars 81 G 5 THE MINOR PLANETS APPENDIX G ASTRONOMICAL PHENOMENA The terrestria
4. porpoisehead net gt Paul Robinson lt probinson at directspecs dot co dot uk gt Andras Mohari lt mayday at mailpont dot hu gt Rudy Gobits lt R Gobits at xs4all dot nl gt Dirk Schwarzhans lt mei mail at gmx dot de gt Barry Gerdes lt barrygastro at hotmail dot com gt sigma sigma cosmos dot door at gmail dot com The diagram is a modification of a diagram by Richard Powell who kindly granted permission for it to be distrubuted under the FDL Project coordinator Fabien Ch reau Developer Johannes Gajdosik Graphic other designer Johan Meuris Developer Rob Spearman Additional material has been incorporated into the guide from sources that are pub lished under the GNU FDL including material from Wikipedia and the Astronomy book at Wikibooks 96 Bibliography 1 Douglas Adams The Hitchhiker s Guide to the Galaxy Pan Macmillan 1979 2 L H Aller I Appenzeller B Baschek H W Duerbeck T Herczeg E Lamla E Meyer Hofmeister T Schmidt Kaler M Scholz W Seggewiss W C Seitter and V Weidemann Landolt B rnstein Numerical Data and Functional Relationships in Science and Technology New Series 1989 3 Mark R Chartrand and Wil Tirion charts National Audubon Society Field Guide of the Night Sky Alfred A Knopf Inc 1991 4 Robert Dinwiddie Ian Ridpath Pam Spence Giles Sparrow Carole Stott David Hughes Kevin Tildsley Philip Eales and Iain Nicolson Universe Dorling Kinders
5. used to build Stellarium for all binary releases For developers who build Stellarium using the SDL library this listbox will show available full screen resolutions 22 4 6 LANGUAGE SETTINGS CHAPTER 4 CONFIGURATION Turns on the drawing of the stars The drawing of the Sun is not affected Stars Names Up to mag Turns on the labelling of named stars There is a spin box next to this option which controls the brightest magnitude of the stars that are la belled remember the lower the number the brighter the star Star Twinkle Amount Turns on star twinkles There is a spin box for setting the amount of Constellations Lines Turns on the drawing of the lines between stars that help to visualise the Ra NNNM Nebulas Names Up to mag Turns on the drawing of nebulae and galaxies A limit may be set as to the magnitude of the objects which will be shown Also display Nebulas without textures When selected nebulae for which there are no images are also displayed e T ngu Turns on drawing of the planets Mercury Venus etc Moon Scale Magnifies the size of the moon by 4x People perceive the Moon to have a larger angular size than it actually does This feature compensates for this illusion which doesn t apply so much to computer screens as it does in the sky Planets Hints Draws a small circle around the planets and labels them with the ap ee Equatorial Grid Draws grid lines for the RA Dec coordinate system see
6. It is a truly gigantic gas and dust cloud that extends for several hundred light years reaching almost halfway across the constellation of Orion The nebula contains a cluster of hot young stars known as the Trapezium and more stars are believed to be forming within the cloud La Superba is a Carbon Star a group of relatively cool gigantic usually variable stars that have an outer shell containing high levels of carbon This shell is very ef ficient at absorbing short wavelength blue light giving carbon stars a distinctive red or orange tint This pair are of different spectral type and 52 Bootis at approximately 800 light is twice as far away as 53 Appendix I Exercises I 1 Find M31 in Binoculars M31 the Andromeda Galaxy is the most distant object visible to the naked eye Finding it in binoculars is a rewarding experience for new comers to observing L1 1 Simulation 1 Set the location to a mid Northern latitude if necessary M31 isn t visible for South ern hemisphere observers The UK is ideal 2 Find M31 and set the time so that the sky is dark enough to see it The best time of year for this at Northern latitudes is Autumn Winter although there should be a chance to see it at some time of night throughout the year 3 Set the field of view to 6 or the field of view of your binoculars if they re different 6 is typical for 7x50 bins 4 Practise finding M31 from the bright stars in Cassiopei
7. apparent 71 75 77 main sequence 18 67 Mars 81 Mercury 81 Messier 85 Messier Charles Meteor meteor craters meteor shower 6 Meteorites 84 Meteoroids Milky Way milli arc second 70 minor planets 82 minutes of arc 70 Miranda mirror 22 Moon 1 23 B0 80 moon 37 multiple star systems 75 nadir 31 67 naked eye 88 named stars 23 navigation nebula nebulae 23 83 85 nebulae textures obliquity of the ecliptic 71 observer BI OpenGL 7 optical doubles 76 optical multiples 76 orbit orbital plane panorama 31 INDEX parallax 60 69 72 85 parsec 69 71 74 perspective projection phases 80 planet 23 B7 71 81 Earth 81 hints Jupiter Mars Mercury 23 8 1 Neptune 81 Pluto Saturn Uranus Venus planetarium 6 planetary bodies 37 planetary nebulae planetoids PNG BBA Pogson Norman 71 pole celestial 66 67 72 Earth pole star 72 precession 69 72 presentations 29 projection mode fisheye perspective stereographic proper motion 60 61 74 85 proper name 88 RA 67 RA Dec 77 resolution 22 28 right ascension 67 72 77 Russell Henry Norris 78 satellite 80 Saturn 13 82 screen mode screen resolution 22 screenshot save directory 25 script bar 28 30 script save directory scripts 29 editing hi
8. flag enable move mouse doesn t seem to do very much init fov initial field of view in degrees typical value 60 navigation init view pos floats initial viewing direction This is a vector with x y z coordinates x being N S S ve y being E W E ve z being up down up ve Thus to look South at the horizon use 1 0 0 To look Northwest and up at 45 use 1 1 1 and so on navigation auto move duration float duration for the program to move to point at g prog an object when the space bar is pressed Typ ical value 7 4 navigation mouse_zoom float Sets the mouse zoom amount mouse wheel g navigation move speed float Sets the speed of movement g navigation Zoom speed float Sets the zoom speed g navigation viewing mode string if set to horizon the viewing mode simu late an alt azi mount if set to equatorial the viewing mode simulates an equatorial mount navigation flag manual zoom bool set to true if you want to auto zoom in incre p gemere landscape flag langscape bool set to false if you don t want to see the land qe M landscape flag fog bool set to false if you don t want to see fog on landscape flag atmosphere bool set to false if you don t want to see atmo pe qme qeu fl landscape ag landscape sets bool set to true if you want Stellarium to mod ify the observer location when a new land scape is selected changes planet and longi tude latitude altitude if that data is a
9. sets the longitude coordinate of the observer Value is in degrees minutes seconds Posi tive degree values mean East negative West e g 01d37 6 00 init location altitude observer s altitude above mean sea level in pem cc init location landscape name sets the landscape you see Other options are pee guereins trees hurricane hogerielen init location time zone 8 sets the time zone At time of writing the pee ieee oo only valid value is system_default init_location time display format string set the time display format mode can be sys SE eee init location date display format 5 set the date display format mode can be sys tem_default mddyyyy ddmmyyyy or yyyym mdd ISO8601 49 APPENDIX A CONFIGURATION FILE init_location home_planet string name of solar system body on which to start stellarium This may be set at runtime from the TUI menu removable_media_path Path to removable media CD DVD This is usually only used in Digitalis planetarium products 50 Appendix B Scripting Commands Command Argument Names Argument Values Notes audio action pause play sync Audio functions are only available if Stellaium was com piled with the audio options If this is not the case a mes sage should be printed at startup to the terminal OSX Linux or stdout txt Windows stating This executable was compiled without audio support filename AUDIO FILENAME Used with play action Forma
10. 0 1 0 for white color chart_color float R G B sets the colour of the chart in RGB values night_color where is the maximum e g 0 0 1 0 chart_color for white color telescope_circle_color floar R G B sets the colour of the telescope location indi cator RGB values where is the maximum e g 1 0 1 0 1 0 for white color telescope_label_color floar R G B sets the colour of the telescope location la bel RGB values where is the maximum e g 1 0 1 0 1 0 for white flag show gravity ui color night color chart color tui flag show tui datetime bool set to true if you want to see a date and time BEEF tui flag_show_tui_short_obj_inffo bool set to true if you want to see object info eee 46 APPENDIX A CONFIGURATION FILE navigation preset_sky_time float preset sky time used by the dome ver sion Unit is Julian Day Typical value 2451514 250011573 navigation startup time mode string set the start up time mode can be actual start with current real world time or Preset start at time defined by preset sky time flag enable zoom keys set to false if you want to disable the zoom keys navigation flag manual zoom bool set to false for normal zoom behaviour as decribed in this guide When set to true the auto zoom feature only moves in a small amount and must be pressed many times navigation flag enable move keys bool set to false if you want to disable the arrow porc navigation
11. 3 Editing Script 5 5 5 Scripting Hints and Tip 5 7 1 Single Fish eve Method 5 7 4 landscape ini location sectio 5 8 3 Modifying nebula textures fab 5 8 4 Editing Image File 5 10 Adding Planetary Bodie 5 11 Other Configuration File 5 12 Taking Screenshot 5 13 3 Keyboard Control 5 14 Image Flipping A Configuration file B Scripting Commands C Precisio D 1 Stellarium s Sky Mode D 2 Star Catalogue File Format D 2 1 General Descriptio D 2 2 File Section D 2 3 1 File Header Record D 2 3 3 Star Data Record E Creating a Personalised Landscape for Stellariu E 0 6 Removing the background to make it transparent Examples lees Running 55 4 Examplescripl 5 6 VisualEffectd 5 6 1 LiehtPolluion 5 7 Customisine Landscaped 5 7 2 Single Panorama Method 5 7 3 Multiple Image Method 5 8 Adding NebulaeImaged 5 8 1 Modifying 2000 5 8 2 Modifying nqc2000names dat 59 Sky Cultured e n n AR 5 13 Telescope 5 13 1 Telescope 5 5 132 Dll Zonedg xe 2 3__
12. 4 Show 4 2 Star Magnitude Multiplier 4 3 Maximum Magnitude to Label 4 4 Twinkling 5 Colors 9 Constellation Lines 2 2 Constellation Names 5 3 Constellarion Art Intensity 5 4 Constellation Boundaries 5 5 Cardinal Points 5 6 Planet Names 5 7 Planet Orbits 5 8 Planet Trails 5 9 Meridian Line 5 10 Azimuthal Grid 5 11 Equatorial Grid 5 12 Equator Line 5 13 Ecliptic Line 5 14 Nebula Names 5 15 Nebula Circles 6 Effects 6 Light Pollution Luminance 6 2 Landscape 6 3 Manual zoom 6 4 Object Sizing Rule 6 5 Magnitude Sizing Multiplier 6 6 Milky Way intensity 6 7 Maximum Nebula Magnitude to Label 6 8 Zoom Duration 6 9 Cursor Timeout 6 10 Setting Landscape Sets Location 7 Scripts 75 Local Script 7 2 CD DVD Script 8 Administration 8 Load Default Configuration 8 2 Save Current Configuration as Default 8 3 Shutdown 17 8 4 Update me via Internet 8 5 Set UI Locale Table 3 8 Text user interface menu Chapter 4 Configuration Most of Stellarium s configuration is done using the configuration window To open the configuration window click the button on the main tool bar You can also press the 1 key digit one to open the configuration window The window has several tabs for configuring various aspects of the program In addition to the configuration window some operations may also be performed using the text menu see section B L Some options may only be configured by e
13. Depending upon conditions six to 9 of the Seven Sisters Aldebaran in Taurus and Almaak in blueish stars in this famous cluster will be Andromeda visible to someone with average eyesight and in binoculars it is a glorious sight The cluster has more than 500 members in to tal many of which are shown to be sur rounded by nebulous material in long ex posure photographs Algol The Demon Star Variable Star 3 0 Avg Halfway between Aldebaran in Once every three days or so Algol s bright Beta Persei Taurus and the middle star of the ness changes from 2 1 to 3 4 and back W of Cassiopeia within a matter of hours The reason for this change is that Algol has a dimmer gi ant companion star with an orbital period of about 2 8 days that causes a regular partial eclipse Although Algol s fluctua tions in magnitude have been known since at least the 17th century it was the first to be proved to be due to an eclipsing compan ion it is therefore the prototype Eclipsing Variable Sirius Alpha Canis Majoris Star 1 47 Sirius is easily found by following Sirius is a white dwarf star at a compara the line of three stars in Orion s belt tively close 8 6 light years This proximity southwards and it s high innate luminance makes it the brightest star in our sky Sirius is a double star it s companion is much dimmer but very hot and is believed to be smaller than the earth M44 i Open Cluster 3 7 Cancer lies about halfway between There
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15. Location lon 11d40 15 lat 48d15 36 443 m Planet Earth Setting landscape updates the location Info A view from the ESO headquarters in Garching bei Munchen Germany Save as default Figure 4 3 Changing the landscape If the Setting landscape updates the location box is checked changing the landscape will also change the location of the observer This will set the home planet as well if the landscape which is selected is for a different planet 20 4 4 VIDEO MODE SETTINGS CHAPTER 4 CONFIGURATION 4 4 Video Mode Settings Configuratior Video Projection Screen Resolution perspective orthographic stereographic cylinder Disc Viewport program for apply Viewport Distorter o apply Save as default Figure 4 4 Setting up the video mode The Video tab in the configuration window figure 4 4 offers the following setting options Projection Selecting items in this list changes the projection method which Stellarium uses to draw the sky Options are perspective Perspective projection keeps the horizon a straight line The maximum field of view is 150 The mathematical name for this projection method is gnomonic projection orthographic Orthographic projection is related to perspective projection but the point of perspective is set to an infinite distance The maximum field of view is 180 equal area The full name of this projection method is Lambert azimuthal equal are
16. M GNE ee viewing flag gravity labels bool set to true if you want labels to undergo al viewing flag_moon_scaled bool change to false if you want to see the real Pee viewing moon_scale float sets the moon scale factor to correlate to our perception of the moon s size Typical value 4 viewing constellation_art_intensity float this number multiplies the brightness of the constellation art images Typical value 0 5 viewing constellation art fade duratjoffloat sets the amount of time the constellation art takes to fade in or out in seconds Typical value 1 5 flag planets set to false to hide the planet labels on start up astro flag planets hints bool set to false to hide the planet hints on start up names and circular highlights astro flag planets orbits bool set to true to show the planet orbits on start up fl astro ag light travel time bool set to true to improve accuracy in the move ment of the planets by compensating for the time it takes for light to travel This has an impact on performance 48 APPENDIX A CONFIGURATION FILE astro flag_object_trails bool turns on and off dawing of object trails which show the movement of the planets over time flag_nebula set to false to hide the nebulae on start up flag_nebula_name set to true to show the nebula labels on start up astro flag_nebula_long_name bool set to true to show the nebula long labels on start up
17. Stellarium in both night time left and day time right 3 1 Tour After you run Stellarium for the first time you will see a something like one of the sides of the image shown in Figure B 1 depending on the time of day that you start the program At the top of the screen you will see the date the time Stellarium s version number the location of the observer the field of view FOV and the current frame rate FPS In the bottom left corner of the screen is the main tool bar In the bottom right corner of the screen is the time tool bar The rest of the screen is a graphical representation of the sky and the ground 3 1 TOUR CHAPTER 3 INTERFACE GUIDE 3 1 1 Time Travel When Stellarium starts up it sets it s clock to the same time and date as the system clock However Stellarium s clock is not fixed to same time and date as the system clock or indeed to the same speed We may tell Stellarium to change how fast time should pass and even make time go backwards So the first thing we shall do is to travel into the future Let s take a look at the time tool bar table B 2 If you hover the mouse cursor over the buttons a short description of the button s purpose and keyboard shortcut will appear a Decrease the rate at which time passes DJ Make time pass as normal ime pas Increase the rate at which time passes Return to the current time amp date Table 3 2 Time control tool bar buttons OK so lets
18. This is the proper motion of the ee E 68 bits unsigned int 7 bits This is the magnitude level in B V colour This value refers to one of 256 discrete steps in the magnitude range for the file 75 bits unsigned int 5 bits This is the magnitude level in the V I colour This value refers to one of 256 discrete steps in the magnitude range for the file Table D 12 Star Data Record Type 1 18 bits This is the position of the star relative to the central point in the star s zone in axis 1 xl 18 bits 18 bits This is the position of the star relative to the central point in the star s zone in axis 2 b_v 36 bits unsigned int 7 bits This is the magnitude level in B V colour This value refers to one of 256 discrete steps in the magnitude range for the file mag 43 bits unsigned int 5 bits This is the magnitude level in the V I colour This value refers to one of 256 discrete steps in the magnitude range for the file Table D 14 Star Data Record Type 2 61 Appendix E Creating a Personalised Landscape for Stellarium by Barry Gerdes 2005 12 19 Although this procedure is based on the Microsoft Windows System the basics will apply to any platform that can run the programs mentioned or similar programs on the preferred system The first thing needed for a personalised landscape to superimpose on the horizon dis play is a 360 panorama with a transparent background To make this you will need the following e A di
19. ag _ astro flag nebula display no text urbool set to true to supress displaying of nebula textures 5 fl ag milky way set to false to hide the Milky Way astro milky way intensity float sets the relative brightness with which the milky way is drawn Typical value 1 to 10 astro max mag nebula name float sets the magnitude of the nebulae whose name is shown Typical value 8 astro nebula scale float sets how much to scale nebulae a setting of 1 will display nebulae at normal size astro flag bright nebulae bool set to true to increase nebulae brightness to enhance viewing less realistic flag nebula ngc enables disables display of all NGC objects astro flag telescopes bool enables telescope control if set to true stel larium will attempt to connect to a telescope server according to the values in the tele scopes section of the config file astro flag telescopes name bool enables disables name labels on telescope in dicators telescopes telescope number In this section the ID is the nmber of the tele scope and the value is a colon separated list of parameters name protocol hostname port number delay init location name sets your location s name This is an arbi trary string For example Paris init location latitude sets the latitude coordinate of the observer Value is in degrees minutes seconds Pos itive degree values mean North negative South e g 55d14 30 00 init location
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21. attractive in that it is intuitive most people are familiar with azimuth angles from bearings in the context of navigation and the altitude angle is something most people can visualise pretty easily However the altitude azimuth coordinate system is not suitable for describing the gen eral position of stars and other objects in the sky the altitude and azimuth values for an object in the sky change with time and the location of the observer Stellarium can draw grid lines for altitude azimuth coordinates Use the button on the main tool bar to activate this grid or press the z key F 2 2 Right Ascension Declination Coordinates Like the Altitude Azimuth system the Right Ascension Declination RA Dec coordinate system uses two angles to describe positions in the sky These angles are measured from standard points on the celestial sphere Right ascension and declination are to the celestial sphere what longitude and latitude are to terrestrial map makers The Northern celestial pole has a declination of 90 the celestial equator has a declina tion of and the Southern celestial pole has a declination of 90 67 E2 COORDINATE SYSTEMS APPENDIX ASTRONOMICAL CONCEPTS zenith altitude nadir Figure E 1 Altitude amp Azimuth zenith North pole South pole nadir Figure E2 Right Ascension amp Declination 68 UNITS APPENDIX ASTRONOMICAL CONCEPTS Right ascension is measured as an angle r
22. author recommends the GNU Image Manipulation Program GIMP since it is more than up to the job and is free software in the same spirit as Stellarium itself 36 5 10 ADDING PLANETARY BODIES CHAPTER 5 ADVANCED USE Table 5 6 Sky culture configuration files 5 9 Sky Cultures Sky cultures are defined in the skycultures directory which may be found in the instal lation directory and or user directory Inside is one sub directory per sky culture each of these containing settings and image files as described in table 5 6 Section names should be unique within the ssystem ini file constellation names eng fab This file contains a list of names for each constel lation from the three latter abbreviation of the con stellation constellationsart fab This file contains the details of pictorial representa tions of the constellations fields are 1 Constellation abbreviation 2 image filename This will be appended to skycultures culturename Should include the png extension Note this is case sensitive Star 1 x position in image pixel Star 1 y position in image pixel Star 1 HP catalogue number Star 2 x position in image pixel Star 2 y position in image pixel Star 2 HP catalogue number Star 3 x position in image pixel Star 3 y position in image pixel Star 3 HP catalogue number constellationship fab Describes the lines for the constellations The fields are 1 Constellation
23. calendar days or sidereal days This option only makes sense for Digitalis planetariums Values calendar or sidereal sets the colour of the azimuthal grid in RGB values where is the maximum e g 1 0 1 0 1 0 for white these three numbers determine the colour of the interface in RGB values where is the maximum e g 0 1 0 1 0 for white these three numbers determine the colour of the text in RGB values where is the maxi mum e g 0 1 0 1 0 for white sets the colour of the equatorial grid in RGB values where is the maximum e g 1 0 1 0 1 0 for white sets the colour of the equatorial line in RGB values where is the maximum e g 1 0 1 0 1 0 for white sets the colour of the ecliptic line in RGB is the maximum e g values where 1 0 1 0 1 0 for white APPENDIX A CONFIGURATION FILE color meridian_color sets the colour of the meridian line in RGB night_color values where is the maximum e g chart_color 1 0 1 0 1 0 for white color const_lines_color float R G B sets the colour of the constellation lines in night_color RGB values where is the maximum e g chart_color 1 0 1 0 1 0 for white color const_names_color float R G B sets the colour of the constellation names in night_color RGB values where is the maximum e g chart_color 1 0 1 0 1 0 for white color const_boundary_color float R G B sets the colour of the constellation bound night_color aries in RGB values whe
24. dark clear nights we can see a large beautiful area of diffuse light in the sky It is this for which we name our galaxy The reason for this effect is that our galaxy is somewhat like a disc and we are off to one side Thus when we look towards the centre of the disc we see more a great concentration of stars there are more star in that direction As we look out away from the centre of the disc we see less stars we are staring out into the void between galaxies G 8 Nebulae Seen with the naked eye binoculars or a small telescope a nebula plural nebulae are fuzzy patches on the sky Historically the term referred to any extended object but the modern definition excludes some types of object such as galaxies Observationally nebulae are popular objects for amateur astronomers they exhibit complex structure spectacular colours and a wide variety of forms Many nebulae are bright enough to be seen using good binoculars or small to medium sized telescopes and are a very photogenic subject for astro photographers Nebulae are associated with a variety of phenomena some being clouds of interstellar dust and gas in the process of collapsing under gravity some being envelopes of gas thrown off during a supernova event so called supernova remnants yet others being the remnants of solar systems around dead stars planetary nebulae Examples of nebulae for which Stellarium has images include the Crab Nebula M1 which is a supernova
25. max fov float Set the maximum field of view for the spheric mirror distorter in degrees Typical value 180 spheric mirror flag use ext framebuffer olpjdsbolean Some video hardware incorrectly claims to support some GL extension GL FRAMEBUFFER EXT If when using the spheric mirror distorter the frame rate drops to a very low value e g 0 1 FPS set this parameter to false to tell Stellarium ignore the claim of the video driver that it can use this extension spheric mirror Flip the projection horizontally 43 APPENDIX A CONFIGURATION FILE spheric_mirror boolean Flip the projection vertically spheric_mirror projector_gamma float This parameter controls the properties of the pu spheric mirror projector position x float This parameter controls the properties of the pem spheric mirror projector position y float This parameter controls the properties of the prey spheric mirror projector position z float This parameter controls the properties of the po spheric mirror mirror position x float This parameter controls the properties of the p ipee spheric mirror mirror position y float This parameter controls the properties of the p spheric mirror mirror position z float This parameter controls the properties of the pee spheric mirror mirror radius float This parameter controls the properties of the pu spheric mirror dome radius float This parameter controls the properties of the eee spheric mirror zen
26. prevent over writing existing files Stellarium creates screenshots in different directories depending in your system type see section 5 1 5 13 Telescope Control Stellarium has a simple control mechanism for motorised telescope mounts The user se lects an object i e by clicking on something a planet a star etc and presses the telescope go to key see section 5 13 3 and the telescope will be guided to the object Multiple telescopes may be controlled simultaneously WARNING Stellarium will not prevent your telescope from being pointed at the Sun It is up to you to ensure proper filtering and safety measures are applied 5 13 1 Telescope Servers Stellarium does not control the telescope directly Instead it talks to another program called a telescope server The telescope server translates instructions from Stellarium into the pro 40 5 13 TELESCOPE CONTROL CHAPTER 5 ADVANCED USE Figure 5 2 Telescope control tocol for a given type of telescope mount providing an interface to Stellarium over TCP IP networking Each telescope to be controlled has one instance of a telescope server which listens to a TCP port which Stellarium connects to Up to ten telescopes may be controlled by Stellarium at one time At time of writing there are three telescope server types implemented a dummy test telescope server a telescope server for the Meade LX200 and a telescope server for Cele stron NexStar telescopes The teles
27. quality of the graphics that Stellarium pro duces it is used in some real planetarium projector products Some amateur astronomy groups use it to create sky maps for describing regions of the sky in articles for newsletters and magazines Stellarium is under fairly rapid development and by the time you read this guide a newer version may have been released with even more features that those documented here Check for updates to Stellarium at the Stellarium webite If you have questions and or comments about this guide please email author For comments about Stellarium itself visit the Chapter 2 Installation 2 1 System Requirements e Linux Unix Windows 95 98 2000 NT XP or MacOS X 10 3 x or greater e A 3D graphics card with a support for OpenGL e A dark room for realistic rendering details like the Milky Way or star twinkling can t be seen in a bright room e Minumum of 256 MiB RAM 1 GiB required for the largest star catalogues 2 20 Downloading You should visit the Stellarium website Download packages for various platforms are available directly from the main page Choose the correct package for your operating syste 2 3 Installation 2 3 1 Windows 1 Double click on the stellarium 0 9 0 exe file to run the installer 2 Follow the on screen instructions 2 3 2 MacOS X 1 Locate the stellarium 0 9 0 dmg file in finder and double click on it or open it using the disk copy progra 2 Have a browse of
28. scripts sub folder of the user directory 5 1 2 MacOS X installation directory This is found inside the application bundle Stellarium app See the Inside Application Bundles for more information user directory This is the Library Preferences Stellarium sub directory of the users home directory screenshot save directory Screenshots are saved to the users Desktop script save directory Recorded scripts will be saved in the scripts sub folder of the user directory 5 1 3 Linux installation directory This is in the share stellarium sub directory of the installation prefix i e usually usr share stellarium or usr local share stellarium user directory This 15 the stellarium sub directory of users home directory i e stellarium screenshot save directory Screenshots are saved to the users home directory script save directory Recorded scripts will be saved in the scripts sub folder of the user directory i e stellarium scripts 5 1 4 Directory Structure Within the installation directory and user directory defined in section 5 T files are ar ranged in the following sub directories landscapes contains data files and textures used for Stellarium s various landscapes Each landscape has it s own sub directory The name of this sub directory is called the landscape ID which is used to specify the default landscape in the main configura tion file skycultures contains constellations common star names and
29. section Equator Line Draws the celestial equator line Azimuthal Grid Draws grid lines for the Altitude Azimuth coordinate system see sec tion E 2 1 Ecliptic Line Draws the ecliptic line Ground Draws the ground If this option is de selected the ground becomes transparent Note that the daylight effects go a bit weird if you do this so it s usually a good idea to turn of atmosphere if you turn off ground It might also be helpful to use the equatorial coordinate system when the ground is turned off Cardinal Points Draws markers for North South East and West on the horizon Atmosphere Draws atmospheric effects This means the sky brightens when the sun is above the horizon and that there is a haze around the moon og Draws a slight fog near to the horizon Changes the rate at which meteors are displayed Table 4 2 Display options in the configuration window rendering tab 23 4 6 LANGUAGE SETTINGS CHAPTER 4 CONFIGURATION Language Program Lang a Sky La azarbaycan dili azerbaycan dili Catal Catal esky esky dansk dansk Deutsch Deutsch EAAnviuk EAAnviuk Sky Culture Chinese Egyptian Inuit Korean Lakota Save as default Figure 4 6 Configuration window language tab this setting you must save settings and re start stellarium for your changes to take effect Sky Language This is the language used to label astonomical objects such as the planets Changes to this setting come in
30. set the location date time and time zone e The clear command is a useful starting point from which to set the display flags 5 6 Visual Effects 5 6 1 Light Pollution Stellarium can simulate light pollution This effect is turned on by using the TUI menu Press the m key and navigate to item 6 1 Light Pollution Luminance If the value of this setting is greater than 0 an orange glow will be seen in the night sky The higher the value the greater the brightness of the light pollution The brightness of the light pollution will affect the brightness of the stars which are visible at a given zoom level the more light pollution the brighter stars have to be to be visible 30 5 7 CUSTOMISING LANDSCAPES CHAPTER 5 ADVANCED USE 5 7 Customising Landscapes It is possible to create your own landscapes for Stellarium There are three types of land scape Single Fish eye Method Using a fish eye panorama image Single Spherical Method Using a spherical panorama image Multiple Image Method also called old style landscapes Using a series of images split from a 360 strip panorama image a ground image Each landscape has it s own sub directory in user directory gt landscapes or lt installation directory gt landscapes The name of the sub directory is called the landscape ID The sub directory must contain a file called 1andscape ini which describes the landscape type texture filenames and other data Texture files fo
31. that orbits the Sun and at least occasionally exhibits a coma or atmosphere and or a tail Comets have a very eccentric orbit very elliptical and as such spend most of their time a very long way from the Sun Comets are composed of rock dust and ices When they come close to the Sun the heat evaporates the ices causing a gaseous release This gas and loose material which comes away from the body of the comet is swept away from the Sun by the Solar wind forming the tail Comets whose orbit brings them close to the Sun more frequently than every 200 years are considered to be short period comets the most famous of which is probably Comet Halley named after the British astronomer Edmund Halley which has an orbital period of roughly 76 years G 6 Galaxies Stars it seems are gregarious they like to live together in groups These groups are called galaxies The number of stars in a typical galaxy is literally astronomical many billions sometimes ever hundreds of billions of stars Our own star the sun is part of a galaxy When we look up at the night sky all the stars we can see are in the same galaxy We call our own galaxy the Milky Way or sometimes simply the Galaxy OK it s a silly thing to say gas giants really aren t something you can take down the local swimming pool and throw in the deep end It s a nice thought though 82 G 7 THE MILKY WAY APPENDIX G ASTRONOMICAL PHENOMENA Other galaxies appear i
32. the sky decor_angle_shift vertical angular offset of the scenery textures at which height are the side textures placed decor_angle_rotatez angular rotation of the scenery around the vertical axis This is handy for rotating the landscape so North is in the correct direction ground_angle_shift vertical angular offset of the ground texture at which height the ground texture is placed ground_angle_rotatez angular rotation of the ground texture around the vertical axis When the sides are rotated the ground texturer may beed to me ratated as well to match up with the sides fog_alt_angle vertical angular size of the fog texture how fog looks fog angle shift vertical angular offset of the fog texture at what height is it drawn draw_ground_first if 1 the ground is drawn in front of the scenery i e the side textures will overlap over the ground texture Note that the name of the section in this case guereins must be the landscsape ID i e the same as the name of the directory where the landscape ini file exists A step by step account of the creation of a custom landscape has been contributed by Barry Gerdes See Appendix E 5 7 4 landscape ini location section An example location section location planet Earth latitude 48d10 9 707 longitude 11d36 32 508 altitude 83 Where planet Is the English name of the solar system body for the landscape latitude Is the latitude of site of the l
33. the annual parallax is too small to be a reliable guide Extrinsic variables are stars of constant brightness that show changes in brightness as seen from the Earth These include rotating variables or stars whose apparent brightness change due to rotation and eclipsing binaries 3 Our Moon The Moon is the large satellite which orbits the Earth approximately every 28 days It is seen as a large bright disc in the early night sky that rises later each day and changes shape into a crescent until it disappears near the Sun After this it rises during the day then gets larger until it again becomes a large bright disc again G 3 1 Phases of the Moon As the moon moves round its orbit the amount that is illuminated by the sun as seen from a vantage point on Earth changes The result of this is that approximately once per orbit the moon s face gradually changes from being totally in shadow to being fully illuminated and back to being in shadow again This process is divided up into various phases as described in table G 6 Me 80 G 4 THE MAJOR PLANETS APPENDIX G ASTRONOMICAL PHENOMENA Planets Dwarf Planets Figure G 4 Planets and dwarf planets in our solar system The planet sizes are drawn to scale but not their distances from the Sun or one another G 4 The Major Planets Unlike the stars whose relative positions remain more or less constant the planets seem to move across the sky over time the word
34. the readme file and drag Stellariumto the Applications folder or somewhere else if you prefer Linux users your distribution may already carry Stellarium as part of the distro just look in your package manager Note that at the time of writing there are some problems with the MacOS X installation process See the forums and the wiki for up to date notes 2 4 RUNNING STELLARIUM CHAPTER 2 INSTALLATION 2 3 3 Linux Check if your distribution has a package for Stellarium already if so you re probably best off using it If not you can download and build the source Don t worry it uses automake and autoconf so it s nice and easy see the the wikilfor detailed instructions If you re doing it the manual way dependencies are Some OpenGL implementation e g nvidia GLX e SDL e Zlib libpng amp libjpeg SDL mixer optional for audio support Freetype Boost filesystem threading Freetype Developer toolchain C compiler STL linker libcurl 2 4 Running Stellarium Windows The Stellarium installer creates an item in the Start Menu under in Programs section Select this to run Stellarium MacOS X Double click on Stellarium wherever you put it Linux If your distribution had a package you ll probably already have an item in the Gnome or KDE application menus If not just use a open a terminal and type stellarium Chapter 3 Interface Guide Figure 3 1 A composite screenshot showing
35. to re form the TIFF file with alpha channel Using this trick I did a little patching and painting on the original picture in Paint on the original JPEG form When completed I loaded it into Photoshop and added the blank alpha channel to it I was then able to paste the previously created alpha layer into the new picture It worked perfectly The panorama now needs to be broken up into suitable square images for insertion into a landscape It took me some time to get the hang of this but the process I found best was in The Gimp It was the easiest to cut the main panorama into sections as it has a mask scale in the tool bar Load the panorama file with alpha channel into The Gimp Then using the mask tool cut out the squares of the predetermined size starting from the left hand side of the picture I don t think it is necessary to make them exact squares but I did not experiment with this aspect The position of the cut will be shown on the lower tool bar Accuracy is improved if you use the maximum zoom that will fit on the page Create a new picture from the file menu then select and adjust the size to your pre determined size then select transparent for the background Because of the alpha channel the transparent section will be automatically clipped of much of the trans parent part of the picture Paste the cutting into the new picture If it is smaller 64 10 11 12 13 14 15 APPENDIX E CREATING A PERSONALISED LAN
36. to show the info bar at top of the screen flag_show_date set to false to hide date gui flag_show_appname bool set to true to show the application name in the top bar color night_color chart_color color night_color chart_color color night_color chart_color color night_color chart_color color night_color chart_color color night_color chart_color flag_show_selected_object_i set to false if you don t want info about the selected object flag_show_fps set to false if you don t want to see at how many frames per second Stellarium is ren dering flag_show_fov bool set to false if you don t want to see how EN flag_show_script_bar bool set to true if you want to have access to the pee mouse_cursor_timeout string flag_script_allow_ui flag_show_flip_buttons day_key_mode azimuthal_color gui_base_color gui_text_color equatorial_color equator_color ecliptic_color 45 set to 0 if you want to keep the mouse cursor visible at all times 0 values mean the cursor will be hidden after that many seconds of inactivity when set to false the normal movement con trols will be disabled when a script is playing true enables them enables disables display of the image flip ping buttons in the main toolbar see section Specifies the amount of time which is added and subtracted when the and keys are pressed
37. under the conditions of sections 2 and 3 above provided that you release the Modified Version under precisely this License with the Modified Version filling the role of the Document thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it In addition you must do these things in the Modified Version A Use in the Title Page and on the covers if any a title distinct from that of the Document and from those of previous versions which should if there were any be listed in the History section of the Document You may use the same title as a previous version if the original publisher of that version gives permission B List on the Title Page as authors one or more persons or entities responsible for authorship of the modifications in the Modified Version together with at least five of the principal authors of the Document all of its principal authors if it has fewer than five unless they release you from this requirement C State on the Title page the name of the publisher of the Modified Version as the publisher D Preserve all the copyright notices of the Document E Add an appropriate copyright notice for your modifications adjacent to the other copyright notices F Include immediately after the copyright notices a license notice giving the public permission to use the Modified Version under the terms of this License in the form shown in the Addendum below G Preserve in that lice
38. was a comet hunter and was frustrated by objects which resembled but were not comets He therefore compiled a list of these objects The first edition covered 45 objects numbered M1 to M45 The total list consists of 110 objects ranging from M1 to M110 The final catalogue was published in 1781 and printed in the Connaissance des Temps in 1784 Many of these objects are still known by their Messier number Because the Messier list was compiled by astronomers in the Northern Hemisphere it contains only objects from the north celestial pole to a celestial latitude of about 35 Many impressive Southern objects such as the Large and Small Magellanic Clouds are excluded from the list Because all of the Messier objects are visible with binoculars or small telescopes under favourable conditions they are popular viewing objects for ama teur astronomers In early spring astronomers sometimes gather for Messier Marathons when all of the objects can be viewed over a single night Stellarium includes images of many Messier objects 85 G 12 OBSERVING HINTS APPENDIX ASTRONOMICAL PHENOMENA G 12 Observing Hints When star gazing there s a few little things which make a lot of difference and are worth taking into account Dark skies For many people getting away from light pollution isn t an easy thing At best it means a drive away from the towns and for many the only chance to see a sky without significant glow from street light
39. will only go into the masked area It wont spill over so the job is quite easy When this is done you will have created your alpha layer Check the size of the image and if it is greater than 5000 pixels wide reduce its size by a fixed percentage till it is under this limit The limit was necessary for one of the programs I used but may not be always necessary However any greater resolution will be wasted and the file size will be excessive Save the whole image in the compressed tiff form or PNG form The only formats that preserve the alpha channel This image is the horizon picture Give it a name tif or png whichever format you save it in After making the panorama tif I noticed that the trees still had areas of the original sky embedded that werent blanked by the alpha layer I found that I could add these sections piece by piece to the alpha layer with the magic wand and paint them out This took some time as there were a large number to be removed However the result was worth the effort as it allows the sky display to be seen through the trees Especially at high zooms ins Another little trick I discovered was that the panorama could be saved as a JPEG file no alpha channel and the alpha channel also saved as a separate JPEG file This can save space for transmission And allow manipulation of the original file in another program as long as the skyline is unchanged At a later date the two files can be re combined in Photoshop
40. 74 orbit 71 rotation 69 rotation of 66 eccentric eclipse 6 29 84 eclipsing binaries 75 ecliptic 23 75 elliptical galaxies equator 23 66 67 celestial 67 67 equatorial 23 equatorial grid 67 98 INDEX Eris 81 ESA European Space Agency EXT E3 extended object 83 extended objects 35 extrinsic 80 eyepiece faces 56 field of view DIRI 60 67191 file configuration 27 configuration misc 38 landscape ini 31 32 script fireballs first point of aries 69 fish eye 31 Flamsteed John 77 fog FOV BI full screen mode galaxy 23 B5 geodesic giants Greenwich 69 grid 23 67 equatorial 67 Halley Edmund 82 Hertzsprung Ejnar 78 Hipparchus 71 85 Hipparcos 69 77 835 catalogue experiment home planet 20 horizon 20 23 BO 661 67 icosahedron 56 image files 36 installation directory interstellar clouds intrinsic 80 irregular galaxies Jovian planets JPEG Jupiter BABA landscape 2O 26 32 landscape ID 2d landscapes 20 BI language settings 22 99 INDEX latitude 18 27 67 88 P 1 lenticular galaxies light pollution light year 69 location 18 27 B0 66 67 longitude 13 27 67 69 Luminosity luminosity 78 luminosity class M31 macros magellanic cloud 85 magnitude 15 23 60 61 71 absolute 71 Z5
41. D 72 cm d 21 cm so 21 2 arctan 777 D Q 1 16 2 Remember that handy angles are not very precise depending on your posture at a given time the values may vary by a fair bit I 3 Find a Lunar Eclipse Stellarium comes with two scripts for finding lunar eclipses but can you find one on a different date I 4 Find a Solar Eclipse Find a Solar Eclipse using Stellarium amp take a screenshot of it L5 Script a Messier Tour Write a script which shows a tour of five of your favourite messier objects 1 Make a list of five objects to include in your tour 2 Close Stellarium and create new script file in the user directory scripts directory Call it something ending in sts for example mytour sts 3 Put your scripting commands in the file You should use a regular text editor to edit it e g Notepad 4 Start Stellarium and run your script Hints and tips e You can record actions which you perform in Stellarium using the CTRL r key e Change the main configuration file so that Stellarium runs in windowed mode this way you can edit your script in another window without having to shut down Stellar ium e Enable the script bar to try out commands before adding them to your script 92 Appendix J GNU Free Documentation License Version 1 2 November 2002 Copyright C 2000 2001 2002 Free Software Foundation Inc 51 Franklin St Fifth Floor Boston MA 02110 1301 USA Everyone is permitted t
42. DSCAPE FOR STELLARIUM than your predetermined size it will go to the centre leaving some of the transparent background at the bottom of the picture Save the file in the PNG format Moving the picture to the bottom of the window is much easier in Photoshop although quite possible in The Gimp I repeated steps 8 and 9 till I had all sections of the panorama saved Next I re loaded Photoshop and opened the first of the saved pictures Then from the menu selected the picture with the mask tool and then selected move Next clicking on the picture will cut it out The cutting can now be dragged to the bottom of the frame It will not go any further so there is no trouble aligning This bottom stop did not work on The Gimp and so it was harder to cut and place the picture section It is most important to align the pictures to the bottom Save the picture with the name you intend to call your landscape as xxxxxx1 png Repeat steps 11 and 12 for the rest of the pictures till you have all the elements for your landscape Make a new directory for the landscape This should be a sub directory of either the lt user directory gt landscapes or lt installation gt landscapes directory The name of the directory should be unique to your landscape and is the landscape ID The convention is to use a single descriptive word in lowercase text for example gueriens Place your pictures your new directory In your new landscape directory create a new file
43. Material here is only an overview and the reader is encouraged to get hold of a couple of good books on the subject A good place to start is a compact guide and ephemeris such as the National Audubon Society Field Guide to the Night Sky 3 Also recommended is a more complete textbook such as Universe There are also some nice resources on the net like the Wikibooks Astronomy 5 Celestial Sphere The Celestial Sphere is a concept which helps us think about the positions of objects in sky Looking up at the sky you might imagine that it is a huge dome or top half of a sphere and the stars are points of light on that sphere Visualising the sky in such a manner it appears that the sphere moves taking all the stars with it it seems to rotate If watch the movement of the stars we can see that they seem to rotate around a static point about once a day Stellarium is the perfect tool to demonstrate this 1 Open the configuration window select the location tab Set the location to be some where in mid Northern latitudes The United Kingdom is an ideal location for this demonstration 2 Turn off atmospheric rendering and ensure cardinal points are turned on This will keep the sky dark so the Sun doesn t prevent us from seeing the motion of the stars when it is above the horizon 3 Pan round to point North and make sure the field of view is about 90 4 Pan up so the N cardinal point on the horizon i
44. Stellarium User Guide Matthew Gates 6th June 2007 Copyright 2007 Matthew Gates Permission is granted to copy distribute and or modify this document under the terms of the GNU Free Documentation License Version 1 2 or any later version published by the Free Software Foundation with no Invariant Sec tions no Front Cover Texts and no Back Cover Texts A copy of the license is included in the section entitled GNU Free Documentation License Contents 1 Introductio 2 Installatio 2 1 System Requirement Installation 2 3 2 3 Window TimeTravel 3 1 1 3 1 2 Moving Around the Sky 3 1 4 Object Search Windo 3 1 6 Information Windo 3 1 8 Other Keyboard Command 4 Configuratio 4 1 Setting the Date and Time 4 3 _ Setting the Landscape Graphic 44 Mode Setting 4 5 Rendering Option 4 6 Language Setting Files and Directorie 5 1 1 Window 5 1 2 _ MacOS X 5 1 2 32 MacOS 31 3 Tool bajy 3 1 5 Window 31 7 TheText Menu 42 Setting YourLocation 5 13 Linux 205 5 1 4 Directory Structurd 5 2 The Main Configuration Fila 10 10 11 13 14 14 15 18 18 18 20 21 22 22 CONTENTS 5 3 1 5 4 Getting Extra Star Data 5 5 5 5 2 Recording Script 5 5
45. Such a notice grants a world wide royalty free license unlimited in duration to use that work under the conditions stated herein The Document below refers to any such manual or work Any member of the public is a licensee and is addressed as you You accept the license if you copy modify or distribute the work in a way requiring permission under copyright law A Modified Version of the Document means any work containing the Document or a portion of it either copied verbatim or with modifications and or translated into another language A Secondary Section is a named appendix or a front matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document s overall subject or to related matters and contains nothing that could fall directly within that overall subject Thus if the Document is in part a textbook of mathematics a Secondary Section may not explain any mathematics The relationship could be a matter of historical connection with the subject or with related matters or of legal commercial philosophical ethical or political position regarding them The Invariant Sections are certain Secondary Sections whose titles are designated as being those of Invariant Sections in the notice that says that the Document is released under this License If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant The
46. a and the constellation of Andromeda L1 2 For Real This part is not going to be possible for many people First you need a good night and a dark sky In urban areas with a lot of light pollution it s going to be very hard to see Andromeda I 2 Handy Angles As described in section G 13 your hand at length provides a few useful estimates for angular size It s useful to know if your handy angles are typical and if not what they are The method here below is just one way to do it feel free to use another method of your own construction Hold your hand at arm s length with your hand open the tips of your thumb and little finger as far apart as you can comfortably hold them Get a friend to measure the distance between your thumb and your eye we ll call this D There is a tendency to over stretch the arm when someone is measuring it try to keep the thumb eye distance as it would be if you were looking at some distant object Without changing the shape of your hand measure the distance between the tips of your thumb and little finger It s probably easiest to mark their positions on a piece of 91 1 3 FIND A LUNAR ECLIPSE APPENDIX I EXERCISES paper and measure the distance between the marks we ll call this d Using some simple trigonometry we can estimate the angular distance Repeat the process for the distance across a closed fist three fingers and the tip of the little finger For example for the author
47. a projection The maximum field of view is 360 fisheye Stellarium draws the sky using azimuthal equidistant projection In fish eye projection straight lines become curves when they appear a large angular distance from the centre of the field of view like the distortions seen with very wide angle camera lenses This is more pronounced as the user zooms out The maximum field of view in this mode is 180 stereographic This mode is similar to fish eye projection mode The maximum field of view in this mode is 235 cylinder The full name of this projection mode is cylindrical equidistant projection The maximum field of view in this mode is 233 Disk viewport This check box when selected adds a black circular border around the main view Using the zoom functions to set the field of view it s possible to simulate looking through binoculars or a telescope eyepiece useful if you want to know how much of a constellation you can see at once with a given instrument 21 4 5 RENDERING OPTIONS CHAPTER 4 CONFIGURATION Viewport Distorter This is a special modifier to the projection mode intended for use with a projector and a spherical mirror With this set up it is possible to create a low cost projection system for making a small planetarium Screen resolution In version 0 9 0 the screen resolution list box is not populated for most buildd and can be ignored 4 5 Rendering Options The Rendering tab figure 4 5 in the config
48. abbreviation 2 Number of lines After this are pairs of HP catalogue numbers which the lines are drawn between info ini Contains the name for this sky culture as it will ap UE pine contusion dg age star_names fab Contains a list of HP catalogue numbers and com ERE 5 10 Adding Planetary Bodies Planetary bodies include planets dwarf planets moons comets and asteroids The orbits and physical characteristics of these bodies are described in the data ssystem ini file 37 5 11 OTHER CONFIGURATION FILES CHAPTER 5 ADVANCED USE The file format follows ini file conventions Each section in the file represents the data for one planetary body Each section has values as described in table 5 9 Orbital calculations for the major planets is handled by sophisticated custom algo rithms and is accurate for a comparitively long time For asteroids and comets the cal culations are not as accurate and the data in ssystem ini for these bodies should be updated periodically every year or two At present this must be done manually by editing the ssystem ini file An example entry might look like this ceres name Ceres parent Sun radius 470 oblateness 0 0 albedo 0 113 halo true color 1 0 1 0 1 0 tex halo starl6xl6 png coord_func comet_orbit orbit_TimeAtPericenter 2453194 01564059 orbit_PericenterDistance 2 54413510097202 orbit_Epoch 2453800 5 orbit_MeanAnomaly 129 98342 orbit_SemiM
49. ajorAxis 2 7653949 orbit_Eccentricity 0 0800102 orbit_ArgOfPericenter 73 23162 orbit_AscendingNode 80 40970 orbit_Inclination 10 58687 lighting true sidereal_period 1680 15 5 11 Other Configuration Files In addition to the files discussed in the previous sections Stellarium uses various other data files Many of these files may be edited easily to change Stellarium s See table 5 11 4Not all files in the data directory are listed here only the ones which the advanced user is most likely to want to modify 38 5 11 OTHER CONFIGURATION FILES CHAPTER 5 ADVANCED USE parent string English name of parent body the body which this body orbits e g in the case of our Moon the parent body is Earth halo boolean Tf true the body will have a halo displayed round it when it is color r g b Colour of object when rendered as a point Each of r g b is a So a tex_map string File name of a PNG or JPEG texture file to be applied to the object Texture file is searched for in the textures directory tex_halo string File name of a PNG or JPEG texture file to be used as the halo EE eee tex_big_halo string File name of a PNG or JPEG texture file to be used as the big big_halo_size float The angular size of the big halo texture Typical values range Pete ers between 10 and 200 coord_func string Select the method of calculating the orbit Possible values are ell_orbit comet_orb
50. also possible to add new landscapes or scripts by creating the relevant files and directories within the user directory leaving the installation directory unchanged In this manner different users on a multi user system can customise Stellarium without affecting the other users 5 2 The Main Configuration File The main configuration file is read each time Stellarium starts up and settings such as the observer s location and display preferences are taken from it Ideally this mechanism should be totally transparent to the user anything that is configurable should be configured in the program GUI However at time of writing Stellarium isn t quite complete in this respect Some settings can only be changed by directly editing the configuration file This section describes some of the settings a user may wish to modify in this way and how to do it If the configuration file does not exist in the user directory when Stellarium is started e g the first time the user starts the program one will be created with default values for all settings refer to section 5 1 for the location of the user directory on your operating system The name of the configuration file is config inf The configuration file is a regular text file so all you need to edit it is a text editor like Notepad on Windows Text Edit on the Mac or nano vi gedit etc on Linux The following sub sections contain details on how to make commonly used modifica tions to the co
51. an be discovered about a star including its surface temperature and the presence of various elements in its atmosphere 28 000 50 000 10 000 28 000 7 500 10 000 6 000 7 500 4 900 6 000 3 500 4 900 2 000 3 500 Rd Table G 2 Spectral Types 2800050000 B 100002800 A 7500 10000 600 750 G 24900600 K 350014900 M 200 350 Astronomers groups stars with similar spectra into spectral types denoted by one of the following letters O B A F G K and Type O stars have a high surface temperature up to around 50 000 K while the at other end of the scale the M stars are red and have a much cooler surface temperature typically 3000 K The Sun is a type G star with a surface temperature of around 5 500 K Spectral types may be further sub divided using a numerical suffixes ranging from 0 9 where 0 is the hottest and 9 is the coolest Table shows the details of the various spectral types For about 90 of stars the absolute magnitude increases as the spectral type tends to the O hot end of the scale Thus the whiter hotter stars tend to have a greater luminosity These stars are called main sequence stars There are however a number of stars that have spectral type at the M end of the scale and yet they have a high absolute magnitude These stars have a very large size and consequently are known as giants the largest of these known as super giants There are al
52. and the horizon at the bottom of the screen the top of the screen is the zenith 2 Now click on the map again this time a little further South You should see the positions of the stars jump and the centre of rotation has moved a little further down the screen 3 Click on the map even further towards and equator You should see the centre of rotation have moved down again To help with the visualisation of the celestial sphere turn on the equatorial grid by clicking the button on the main tool bar or pressing the on the e key Now you can see grid lines drawn on the sky These lines are like lines of longitude and latitude on the Earth but drawn for the celestial sphere The Celestial Equator is the line around the celestial sphere that is half way between the celestial poles just as the Earth s equator is the line half way between the Earth s poles F 2 Coordinate Systems 2 1 Altitude Azimuth Coordinates The Altitude Azimuth coordinate system can be used to describe a direction of view the azimuth angle and a height in the sky the altitude angle The azimuth angle is measured clockwise round from due North Hence North itself is East 90 Southwest is 135 and so on The altitude angle is measured up from the horizon Looking directly up at the zenith would be 90 half way between the zenith and the horizon is 45 and so on The point opposite the zenith is called the nadir The Altitude Azimuth coordinate system is
53. andscape in degrees minutes and seconds Positive values represent North of the equator negative values South of the equator 34 5 8 ADDING NEBULAE IMAGES CHAPTER 5 ADVANCED USE longitude Is the longitude of site of the landscape Positive values represent East of the Greenwich Meridian on Earth or equivalent on other bodies Negative values rep resent Western logitude altitude Is the altitude of the site of the landscape in meters 5 8 Adding Nebulae Images Extended objects are those which are external to the solar system and are not point sources like stars Extended objects include galaxies planetary nebulae and star clusters These ob jects may or may not have images associated with them Stellarium comes with a catalogue of about 13 000 extended objects with images of over 100 To add a new extended object add an entry in the nebulae default ngc2000 dat file with the details of the object where is either the installation directory or the user directory See section 5 8 T for details of the file format If the object has a name not just a catalogue number you should add one or more records to the nebulae default ngc2000names dat file See section 5 8 2 for de tails of the file format If you wish to associate a texture image with the object you must also add a record to the nebulae default nebula textures fab file See section 5 8 3 for details of the file format Nebula images should have di
54. ansparent image formats include PNG XCF and JPG Opaque formats include proprietary formats that can be read and edited only by proprietary word processors SGML or XML for which the DTD and or processing tools are not generally available and the machine generated HTML PostScript or PDF produced by some word processors for output purposes only The Title Page means for a printed book the title page itself plus such following pages as are needed to hold legibly the material this License requires to appear in the title page For works in formats which do not have any title page as such Title Page means the text near the most prominent appearance of the work s title preceding the beginning of the body of the text A section Entitled XYZ means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language Here XYZ stands for a specific section name mentioned 93 APPENDIX J GNU FREE DOCUMENTATION LICENSE below such as Acknowledgements Dedications Endorsements or History To Preserve the Title of such a section when you modify the Document means that it remains a section Entitled XYZ according to this definition The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document These Warranty Disclaimers are considered to be included by reference in this License but only as regard
55. are probably 350 or so stars in this E the twins Castor amp Pollux in cluster although it appears to the naked eye Gemini and Regulus the brightest simply as a misty patch It contains a mix star in Leo The Beehive can be ture of stars from red giants to white dwarf found between Asellus Borealis and and is estimated to be some 700 million Asellus Australis years old 27 Cephei Delta Cephei Variable Star 4 0 Avg Locate the four stars that form the Delta Cephei gives it s name to a whole square of Cepheus One corner of class of variables all of which are pulsat the square has two other bright stars ing high mass stars in the later stages of nearby forming a distinctive trian their evolution Delta Cephei is also a dou gle delta is at the head of this tri ble star with a companion of magnitude 6 3 angle in the direction of Cassiopeia visible in binoculars 89 APPENDIX H SKY GUIDE Other Name s eed Loreto Guide Orion Nebula Nebula Almost in the middle of the area bounded by Orion s belt and the stars Saiph and Rigel HP 62223 La Superba X Forms a neat triangle with Phad and Canum Venaticorum Alkaid in Ursa Major Double Star 52 amp 53 Bootis Nu Bootis 1 amp 2 Follow a line from Seginus to Nekkar and then continue for the same distance again to arrive at this double star 90 The Orion Nebula is the brightest nebula visible in the night sky and lies at about 1 500 light years from earth
56. arked reddening of the light as it passes through the atmosphere and this can make the Moon appear a deep red colour G 11 Catalogues Astronomers have made various catalogues of objects in the heavens Stellarium makes use of several well known astronomical catalogues 84 G 11 CATALOGUES APPENDIX G ASTRONOMICAL PHENOMENA G 11 1 Hipparcos Hipparcos for High Precision Parallax Collecting Satellite was an astrometry mission of the European Space Agency ESA dedicated to the measurement of stellar parallax and the proper motions of stars The project was named in honour of the Greek astronomer Hipparchus Ideas for such a mission dated from 1967 with the mission accepted by ESA in 1980 The satellite was launched by an Ariane 4 on 8 August 1989 The original goal was to place the satellite in a geostationary orbit above the earth however a booster rocket failure resulted in a highly elliptical orbit from 315 to 22 300 miles altitude Despite this difficulty all of the scientific goals were accomplished Communications were terminated on 15 August 1993 The program was divided in two parts the Hipparcos experiment whose goal was to measure the five astrometric parameters of some 120 000 stars to a precision of some 2 to 4 milli arc seconds and the Tycho experiment whose goal was the measurement of the astrometric and two colour photometric properties of some 400 000 additional stars to a somewhat lower precision The final Hipparco
57. avels in a year The speed of light being approximately 300 000 kilometres per second means a light year is a very large distance indeed working out at about 9 5 trillion kilometres 9 46073 x 10 km Light years are most frequently used when describing the distance of stars and galaxies or the sizes of large scale objects like galaxies nebulae etc Parsec A parsec is defined as the distance of an object that has an annual parallax of 1 second of arc This equates to 3 26156 light years 3 08568 x 10 km Parsecs are most frequently used when describing the distance of stars or the sizes of large scale objects like galaxies nebulae etc 3 2 Time The length of a day is defined as the amount of time that it takes for the Sun to travel from the highest point in the sky at mid day to the next high point on the next day In astronomy this is called a solar day The apparent motion of the Sun is caused by the rotation of the Earth However in this time the Earth not only spins it also moves slightly round it s orbit Thus in one solar day the Earth does not spin exactly 360 on it s axis Another way to measure day length is to consider how long it takes for the Earth to rotate exactly 360 This is known as one sidereal day Figure E3 illustrates the motion of the Earth as seen looking down on the Earth orbiting the Sun The red triangle on the Earth represents the location of an observer The figure shows the Earth at four times 1 Th
58. awing menu show appname show date show fov show fps constellation names show gravity ui show time show topbar utc time constellation pick ecliptic line enable move enable tui menu enable zoom keys equator line equatorial grid fog gravity labels help infos moon scaled landscape landscape sets location manual zoom menu meridian line milky way nebulae nebula names night object trails planets planet names planet orbits point star Script gui debug show appname show date show fov show fps show gravity ui show script bar show selected objei show time show topbar show tui datetime show tui short obj info star names star twinkle stars track object image action load droj Drop images when no longer needed to improve perfor g P E E mance 52 APPENDIX B SCRIPTING COMMANDS altitude ALTITUDE_ANGLE For positioning the center of the image in horizontal co ordinates Zero is at the horizon 90 is at the zenith azimuth AZIMUTH_ANGLE For positioning the center of the image in horizontal co ordinates Zero is North 90 is East coordinate_system viewport horizontal What coordinate system to use to position the image Must be defined at image load Can not be changed later Default is viewport SECONDS How long to take to complete the command NN i O name IMAGE_NAME Used to refer to the image in later calls to manipulate the image Images must be in PNG format If
59. called landscape ini file I used wordpad Add a line for the landscsape section It s probably easiest to copy the landscape ini file for the Gueriens landscape and edit it Edit the name Guereins in every instance to the name you have given your landscape Dont forget to make the number of tex entries agree with the number of your pictures If you havent made a groundtex picture use one of the existing ones from the file or make a square blank picture of your own idea Because I took my pictures from the roof of the house I used an edited picture of the roof of my house from Google Earth It was pretty cruddy low resolution but served the purpose Next you need to orientate your picture North with true North This is done roughly by making the arrangement of sidel to siden suit your site as close as possible Now you need to edit the value of decor angle rotatez to move your landscape in azimuth Edit decor alt angle to move you landscape in altitude to align your visible horizon angle Edit ground angle rotatez to align your ground with the rest of the landscape Leave the other entries they are suitable as is After re starting Stellarium your landscape will appear in the landscape tab of the config uration window and can be selected as required 65 Appendix F Astronomical Concepts This section includes some general notes on astronomy in an effort to outline some concepts that are helpful to understand features of Stellarium
60. cat andatleast 1 GiB RAM to load the largest file stars 8 2v0 0 cat See section D for details of the contents of these files 28 5 5 SCRIPTING CHAPTER 5 ADVANCED USE Option Option Description Parameter help or h Print a quick command line help message and exit Print the program name and version information and exit config file or config file name Specify the configuration file name The default value is c config ini The parameter can be a full path which will be used verbatim or a partial path Partial paths will be searched for inside the regular search paths unless they start with a which may be used to explicitly specify a file in the current directory or similar For example using the option c my config ini would resolve to the file user directory my config ini whereas c my config ini can be used to explicitly say the file my config ini in the current working directory Table 5 2 Command line options 5 5 Scripting Stellarium has the ability to record and play back sequences of commands in much the same way some applications allow the recording and executing of macros Using this mechanism it is possible to create presentations of astronomical events using Stellarium Two scripts come with Stellarium that explore lunar eclipses More are likely to be included in future releases of Stellariunf Scripts are found either installation directory gt scripts or user directory gt scripts and ha
61. cension followed by the form of the constellation name for example 61 Cygni G 2 4 3 Catalogues As described in section G T1 various star catalogues assign numbers to stars which are often used in addition to other names Stellarium gets it s star data from the Hipparcos catalogue and as such stars in Stellarium are generally referred to with their Hipparcos number e g HP 62223 Figure G 2 shows the information Stellarium displays when a star is selected At the top the common name and Flamsteed designation are shown followed by the RA Dec coordinates apparent magnitude distance and Hipparcos number G 2 5 Spectral Type amp Luminosity Class Stars have many different colours Seen with the naked eye most appear to be white but this is due to the response of the eye at low light levels the eye is not sensitive to colour Typically the unaided eye can start to see differences in colour only for stars that have apparent magnitude brighter than 1 Betelgeuse for example has a distinctly red tinge to it and Sirius appears to be blu Thousands of years ago Sirius was reported in many account to have a red tinge to it a good explanation for this has yet to be found 77 G 2 STARS APPENDIX G ASTRONOMICAL PHENOMENA By splitting the light from a star using a prism attached to a telescope and measuring the relative intensities of the colours of light the star emits the spectra a great deal of interesting information c
62. cession Earth In January 4 3 View from Earth in January View from Earth July Figure 6 Apparent motion due to parallax 73 E6 PROPER MOTION APPENDIX ASTRONOMICAL CONCEPTS of distance called the parsec which is defined as the distance at which a nearby star has p Even the nearest stars exhibit very small movement due to parallax The closest star to the Earth other than the Sun is Proxima Centuri It has an annual parallax of 0 77199 corresponding to a distance of 1 295 parsecs 4 22 light years Even with the most sensitive instruments for measuring the positions of the stars it is only possible to use parallax to determine the distance of stars up to about 1 600 light years from the Earth after which the annual parallax is so small it cannot be measured accurately enough F 6 Proper Motion Proper motion is the change in the position of a star over time as a result of it s motion through space relative to the Sun It does not include the apparent shift in position of star due to annular parallax The star exhibiting the greatest proper motion is Barnard s Star which moves more then ten seconds of arc per year 74 Appendix G Astronomical Phenomena This chapter focuses on the observational side of astronomy what we see when we look at the sky G 1 The Sun Without a doubt the most prominent object in the sky is the Sun The Sun is so bright that when i
63. constellation artwork for Stellarium s many sky cultures Each culture has it s own sub directory in the sky cultures directory scripts contains scripts and files which are used by scripts e g images used in a script nebulae contains data and image files for nebula textures In future Stellarium will be able to support multiple sets of nebula images and switch between them at runtime This feature is not implemented for version 0 9 0 although the directory structure is in place each set of nebula textures has it s own sub directory in the nebulae directory stars contains Stellarium s star catalogues In future Stellarium will be able to support multiple star catalogues and switch between them at runtime This feature is not implemented for version 0 9 0 although the directory structure is in place each star catalogue has it s own sub directory in the stars directory 26 5 2 THE MAIN CONFIGURATION FILE CHAPTER 5 ADVANCED USE data contains miscellaneous data files including fonts solar system data city locations etc textures contains miscellaneous texture files such as the graphics for the toolbar buttons planet texture maps etc If any file exists in both the installation directory and user directory the version in the user directory will be used Thus it is possible to override settings which are part of the main Stellarium installation by copying the relevant file to the user area and modifying it there It is
64. cope server programs accept parameters on the command line port The TCP port on which the program will listen device The name of the serial port device to which the telescope is physically connected e g COMI on a Windows machine or dev ttySO on a Linux machine Note this parameter is not used by the dummer server For example if you have two Meade LX200 telescopes which are connected to your Linux machine on serial ports dev ttyS0 and dev ttyS1 you would start two telescope server programs like this TelescopeServerLx200 10000 dev ttySO amp TelescopeServerLx200 10001 dev ttyS1 amp In this case the two telescope server programs would listen on TCP ports 10000 and 10001 respectively Because Stellarium communicates with the telescope server programs over TCP it is not necessary for the telescope server program to run on the same machine as Stellarium In this way Stellarium is able to control remote telescopes over the Internet See the Stellarium wikilfor more information on how to obtain and build the telescope server programs 5 13 2 Configuration To use telescope control in Stellarium 1 Edit the main configuration file In the astro section set the value of 1ag telescopes and flag telescope name fO true 41 5 14 IMAGE FLIPPING CHAPTER 5 ADVANCED USE name A name for the telescope e g my_1Ix200 Don t use spaces The network protocol Use TCP The name of the computer on which
65. diting the configuration file See section 5 2 for more details 4 1 Setting the Date and Time The second tab in the configuration window is Date amp Time figure A T In this tab you will see controls for adjusting the year month day hour minute and second There is also a display of the current time zone setting and time rate The time zone setting may be set using the TUI see section 3 T 7 for more information 4 2 Setting Your Location The positions of the stars in the sky is dependent on your location on Earth as well as the time and date For Stellarium to show accurately what is or will be was in the sky you must tell it where you are You only need to do this once Stellarium saves your location so you won t need to set it again until you move To set your location choose the Location tab in the configuration window figure E2 There are then three main methodd that you may use to select your location 1 You can set your location by where you live on the map This is convenient but it isn t very precise You can zoom in and out of the map by rolling the mouse wheel and drag zoomed in the map around with the right mouse button 2 If you know your longitude and latitud you might want to can set it using the controls at the bottom of the window Tf you would like to change the date to a long time the past or future it might be more convenient to use the TUI menu as it is possible to select the yea
66. dow provides a convenient way to locate objects in the sky Sim ply type in the name of an object to find and then click the go button or press return Stellarium will point you at that object in the sky As you type Stellarium will make a list of objects which begin with what you have typed so far and the first item in this list will be automatically added to what you are typing after the cursor When you have typed enough letters to get to the object you are interested in you can press return without having to complete the whole name For example suppose we want to locate Mimas a moon of Saturn After typing the first letter of the name m Stellarium makes a list of objects whose name begins with M Mars Miranda Mimas Mercury Moon The first item in this list Mars is automatically filled in for us Pressing return now would go to Mars but we want Mimas so we keep typing After the letter i Miranda is auto completed Again it s not what we want so we continue After the third letter m Mimas is selected so we simply press return or click the go button to locate it This feature can save some typing and is useful for finding objects whose spelling is not certain 13 3 1 TOUR CHAPTER 3 INTERFACE GUIDE 3 1 5 Help Window ing RA DE ed ob recording and During 5 ipping ipping Figure 3 4 The help window The Help window is useful as a quite reference to the key strokes that may be used to co
67. e Header Record describes file wide settings It also contains a magic number which servers as a file type identifier See table D 6 D 2 3 2 Zone Records The Zone Records section of the file lists the number of star records there are per zone The number of zones is determined from the level value in the File Header Record as described in section D T T The Zones section is simply a list of integer values which describe the number of stars for each zone The total length of the Zones section depends on the number of zones See table D 8 D 2 3 3 Star Data Records After the Zones section the actual star data starts The star data records themselves do not contain the zone in which the star belongs Instead the zone is inferred from the position of the record in the file For example if the Zone Records section of the file says that the first 100 records are for zone 0 the next 80 for zone 1 and so on it is possible to infer the zone for a given record by counting how many records have been read so far The actual record structure depends on the value of the Data Type as found in the File Header Record See tables D 10 D T2hnd D T4 for record structure details It should be noted that although the positional data loses accuracy as one progresses though the Star Record Types this is compensated for by the face that the number of zones is much higher for the files where the smaller precision position fields are used so the actual res
68. e Sun is directly overhead it is mid day 69 F3 UNITS APPENDIX ASTRONOMICAL CONCEPTS Figure F 3 Solar and Sidereal days 2 Twelve hours have passed since 1 The Earth has rotated round and the observer is on the opposite side of the Earth from the Sun It is mid night The Earth has also moved round in it s orbit a little 3 The Earth has rotated exactly 360 Exactly one sidereal day has passed since 1 4 It is mid day again exactly one solar day since 1 Note that the Earth has rotated more than 360 since 1 It should be noted that in figure the sizes of the Sun and Earth and not to scale More importantly the distance the Earth moves around it s orbit is much exaggerated In one real solar day the Earth takes a year to travel round the Sun 3654 solar days The length of a siderial day is about 23 hours 56 minutes and 4 seconds It takes exactly one sidereal day for the celestial sphere to make one revolution in the sky Astronomers find sidereal time useful when observing When visiting observatories look out for doctored alarm clocks that have been set to run in sidereal time F 3 3 Angles Astronomers typically use degrees to measure angles Since many observations require very precise measurement the degree is subdivided into sixty minutes of arc also known as arc minutes Each minute of arc is further subdivided into sixty seconds of arc or arc seconds Thus one degree is equal to 3600 second
69. e drawing of constellations Toggle drawing of constellation boundaries Toggle drawing of constellation names Toggle drawing of constellation art Toggle nebulae names off on short on long Toggle drawing of RA Dec grid Cycle through show meridian line show Alt Azi grid neither Toggle drawing of ground Toggle drawing of atmosphere Toggle drawing of horizon fog Toggle drawing of cardinal points N S E W Toggle moon scaling 4x 1x Toggle object tracking moves the view to keep selected object in the centre Toggle drawing of stars Cycle through draw ecliptic draw ecliptic amp planet trails draw neither Toggle drawing of equator line o pe ha o o Z oo o O mne S ee eme ie O Close any open windows help info amp configuration 15 3 1 TOUR CHAPTER 3 INTERFACE GUIDE Time amp Date Time rate pause or script pause when a script is running Po p iesu E Xs pedi ZO po OOO D pe E Increase time rate or increase script speed if a script is running NN E E e mmm B mm 16 3 1 TOUR CHAPTER 3 INTERFACE GUIDE 1 Set Location 15 Latitude 1 2 Longitude 1 3 Altitude m 1 4 Solar System Body 2 Set Time 2 Sky Time 2 2 Set Time Zone 2 3 Days keys 2 4 Preset Sky Time 2 5 Sky Time At Start up 2 6 Time Display Format 2 7 Date Display Format 3 General 3 Sky Culture 32 Sky Language 4 Stars
70. e markings on the ruler are a known angular distance apart e g 1 The markings on the ruler are often marked with luminescent paint for night time use has a nice illustration of the design and use of a crossbow The ruler is held in a curve by a piece of string giving a better indication of the reason for the name The curve is there to make all parts of the ruler perpendicular to the line of sight which improves the accuracy of the device 86 G 13 HANDY ANGLES APPENDIX G ASTRONOMICAL PHENOMENA d 2 arctan 777 Another more handy ahem method is to use the size of your hand at arm s length Tip of little finger About 1 Middle three fingers About 4 Across the knuckles of the fist About 10 Open hand About 18 Using you hand in this way is not very precise but it s close enough to give you some way to translate an idea like Mars will be 45 above the Southeastern horizon at 21 30 Of course there is variation from person to person but the variation is compensated for somewhat by the fact that people with long arms tend to have larger hands In exercise L 2 you will work out your own handy angles 87 Appendix H Sky Guide This section lists some astronomical objects that can be located using Stellarium All of them can be seen with the naked eye or binoculars Since many astronomical objects have more than one name often having a proper name a common name and various cata logue numbers th
71. e table lists the name as it appears in Stellarium use this name when using Stellarium s search function and any other commonly used names The Location Guide column gives brief instructions for finding each object using nearby bright stars or groups of stars when looking at the real sky a little time spent learning the major constellations visible from your latitude will pay dividends when it comes to locating fainter and more interesting objects When trying to locate these objects in the night sky keep in mind that Stellarium displays many stars that are too faint to be visible without optical aid and even bright stars can be dimmed by poor atmospheric conditions and light pollution Stellarum Name Other Name s Dubhe and Merak The Pointers 1 83 2 36 The two rightmost of the seven Northern hemisphere observers are very stars that form the main shape of fortunate to have two stars that point to The Plough Ursa Major wards Polaris which lie very close to the northern celestial pole Whatever the time of night or season of the year they are al ways an immediate clue to the location of the pole star Messier 31 The An Spiral Galaxy 34 Find the three bright stars that con M31 is the most distant object visible to the dromeda Galaxy stitute the main part of the con naked eye and among the few nebulae that stellation of Andromeda From the can be seen without a telescope or power middle of these look toward the ful bi
72. ee directly looking slightly off to the side but concentrating on the object s location can often reveal B Angular distance Learn how to estimate angular distances Learn the angular distances described in section If you have a pair of binoculars find out the angular distance across the field of view and use this as a standard measure G 13 Handy Angles Being able to estimate angular distance can be very useful when trying to find objects from star maps in the sky One way to do this with a device called a crossbo Crossbows are a nice way get an idea of angular distances but carrying one about is a little cumbersome A more convenient alternative is to hold up an object such as a pencil at arm s length If you know the length of the pencil d and the distance of it from your eye D you can calculate it s angular size 0 using this formula 5This curious phenomena is the cause of much childhood anxiety about the dark shapes and patterns which can be seen out of the corner of the eye disappear when looked at directly 6Most binoculars state the field of view somewhere on the body of the instrument Failing that check the documentation if you have any or check with the manufacturer 7 An astronomical crossbow is essentially a stick with a ruler attached to the end The non ruler end of the stick is held up to the face and the user sights along the stick towards the object that is being observed The length of the stick is such that th
73. ermission from the previous publisher that added the old one 94 APPENDIX J GNU FREE DOCUMENTATION LICENSE The author s and publisher s of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version 5 COMBINING DOCUMENTS You may combine the Document with other documents released under this License under the terms defined in section 4 above for modified versions provided that you include in the combination all of the Invariant Sections of all of the original documents unmodified and list them all as Invariant Sections of your combined work in its license notice and that you preserve all their Warranty Disclaimers The combined work need only contain one copy of this License and multiple identical Invariant Sections may be replaced with a single copy If there are multiple Invariant Sections with the same name but different contents make the title of each such section unique by adding at the end of it in parentheses the name of the original author or publisher of that section if known or else a unique number Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work In the combination you must combine any sections Entitled History in the various original documents forming one section Entitled History likewise combine any sections Entitled Acknowledgements and any sections Ent
74. g_show_script_bar true The script bar appears in the main tool bar as a long button containing a gt prompt Clicking on it with the mouse will give it focus it will grab keyboard input After typing a command e g select planet Mercury pressing Enter will execute it You may also use the up and down cursor keys to navigate through previously executed commands 5 2 4 Setting the Time Zone Stellarium tries to determine the time zone based on your system settings It is possible to over ride this by specifying the time zone in the main configuration file init location timezone CET 5 3 Command Line Options Stellarium s behaviour can be modified by providing parameters to the program when it is run via the command line See table 5 2 for a full list 5 3 1 Examples To start Stellarium using the configuration file configuration one ini situated in the user directory stellarium config file configuration one ini stellarium c configuration one ini 5 4 Getting Extra Star Data Stellarium is packaged with over 600 thousand stars in the catalogue but much larger star catalogues are available for download from the To use these catalogues download the files and save them in the stars default sub directory of either the Installation Directory or the User Directory see section 5 1 There are five extra catalogue files available NOTE You should have at least 512 MiB of RAM to load files stars 4 2v0 0 cat to stars 4 2v0 0
75. gital camera on a tripod or stable platform e A program to convert the pictures into a 360 panorama e A program to remove the background and convert the panorama into about 8 square pictures in PNG format for insertion into Stellarium as the sides and if possible a similar square picture of the base you are standing on to form the ground This last requirement is only really possible if this area is relatively featureless as the problem of knitting a complex base is well nigh impossible e Patience Maybe a soundproof room so that the swearing wont be heard when you press the wrong key and lose an hours work E 0 4 The Camera Digital cameras are easy and cheaply available these days so whatever you have should do One mega pixel resolution is quite sufficient The camera needs to be mounted on a tripod so that reasonably orientated pictures can be taken Select a time of day that is quite bright with a neutral cloudy sky so there will be no shadows and a sky of the same overall texture This will make it easier to remove later The pictures were all saved in the JPG format which was used as the common format for all processes up to the removal of the background With a camera that takes 4 3 ratio pictures I found 14 evenly spaced pictures gave the best 360 panorama in the program I used to produce it 62 APPENDIX E CREATING A PERSONALISED LANDSCAPE FOR STELLARIUM Figure E 1 360 panorama E 0 5 Processing into a Panorama Th
76. go see the future Click the mouse once on the increase time speed button EH Not a whole lot seems to happen However take a look at the clock at the top left of the screen You should see the time going by faster than a normal clock Click the button a second time Now the time is going by faster than before If it s night time you might also notice that the stars have started to move slightly across the sky If it s daytime you might be able to see the sun moving but it s less apparent than the movement of the stars Increase the rate at which time passes again by clicking on the button a third time Now time is really flying Let time move on at this fast speed for a little while Notice how the stars move across the sky If you wait a little while you ll see the Sun rising and setting It s a bit like one of those time lapse movies except there are no clouds Stellarium not only allows for moving forward through time you can go backwards too Click on the real time speed button n The stars and or the Sun should stop scooting across the sky Now press the decrease time speed button uH once Look at the clock Time has stopped Click the Decrease time speed button four or five more times Now we re falling back through time at quite a rate about one day every ten seconds Enough time travel for now Wait until it s night time and then click the Real time speed button With a little luck you will now be looking at the night sky 3 1 2 M
77. h a telescope Stellarium can flip the image of the sky in the horizontal and or vertical planes There two ways to do this the keyboard commands CTRL SHIFTth and CTRL4SHIFT v and using the image flipping toolbar buttons The toolbar buttons are not enabled by default To enable them you must edit the main configuration file and set the following options gui flag show flip buttons true 42 Appendix A Configuration file video fullscreen boolean if true Stellarium will start up in full screen mode If false Stellarium will start in win dowed mode video screen_w integer sets the display width value in pixels e g A gt Ha D pd B 768 video bbp mode integer Sets the number of bits per pixel Values 16 24 32 horizontal offset view port horizontal offset vertical offset view port vertical offset video distorter string This is used when the spheric mirror display mode is activated Values include none and fisheye to spheric mirror video minimum fps integer sets the minimum number of frames per sec ond to display at video maximum fps integer sets the maximum number of frames per sec ond to display at This is useful to reduce power consumption in laptops projection type string sets projection mode Values per spective fisheye stereographic fish eye to spheric mirror projection viewport string how the view port looks Values maxi spheric mirror distorter
78. he Trees landscape which comes with Stellarium landscape name Trees type fisheye maptex trees_512 png texturefov 210 Where name is what appears in the landscape tab of the configuration window type identifies the method used for this landscape fisheye in this case maptex is the name of the image file for this landsape texturefov is the field of view that the image covers in degrees 31 5 7 CUSTOMISING LANDSCAPES CHAPTER 5 ADVANCED USE 5 7 2 Single Panorama Method This method uses a more usual type of panorama the kind which is produced directly from software such as autostitich The panorama file should be copied into the lt config root gt landscapes lt landscape_id gt directory and a landscape ini file created The Moon landscape which comes with Stellarium provides a good example of the contents of a landscape ini file for a spherical type landscsape landscape name Moon type spherical maptex apollol7 png Where name is what appears in the landscape tab of the configuration window type identifies the method used for this landscape spherical in this case maptex is the name of the image file for this landsape Note that the name of the section in this case moon must be the landscsape ID i e the same as the name of the directory where the landscape ini file exists 5 7 3 Multiple Image Method The multiple image method works by having a 360 panorama of the hori
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80. ht of the panorama had been greater I could have made fewer pictures and so shown more of the foreground See figure E I E 0 6 Removing the background to make it transparent This is the most complex part of the process and requires a program that can produce transparency to parts of your picture commonly called an alpha channel Two programs I know of will do this The very expensive and sophisticated Adobe Photoshop and a freebee called The Gimp I used Photoshop to produce the alpha channel because selection of the area for trans parency was more positive with the complex skyline I had and I had learnt a little more on how to drive it before I found an executable form of The Gimp For the rest I used a combi nation of both programs I will describe the alpha channel process in detail for Photoshop A lot of this would be suitable for The Gimp as they are very similar programs but I have only tried the bare essential in The Gimp to prove to myself that it could be done 1 Load the panorama picture into Photoshop 2 Create an alpha channel using the channel pop up window This channel was then selected as the only channel visible and it was all black at this stage It needs to be all white To edit this took me some time to discover how What I did was click on Edit in Quick mask mode and then Edit in standard mode This procedure was the only way I found I could edit Click on the magic wand and click it on the channel picture It will pu
81. ial sphere This position for a star is expressed as a 3 dimensional vector which points from the observer at the centre of the geodesic sphere to the position of the star as observed on the celestial sphere D 2 Star Catalogue File Format D 2 1 CGeneral Description Stellarium s star catalogue data is kept in the stars default sub directory of the Installation Directory and or User Directory see section 5 T The main catalogue data is split into several files e stars 0 070 0 cat e stars 1 0vO 0 cat e stars 2 0vO 0 cat e stars 3 070 0 cat e stars 4 1vO 0 cat 56 D 2 STAR CATALOGUE FILE FORMAT APPENDIX D STAR CATALOGUE e stars 5 170 0 cat e stars 6 2v0 0 cat e stars 7 2v0 0 cat e stars 8 2v0_0 cat There also exist some control and reference files e stars hip cids 0v0O 0 cat e stars hip sp 0v0O 0 cat e stars ini e name fab When Stellarium starts it reads the stars ini file from which it determines the names of the other files which it then loads The stars hip cids 0vO 0 cat and stars hip sp 0 0_0 files contain refer ence data for the main catalogue files A given catalogue file models stars for one and only one level i e for a fixed number of zones which is recorded in the header of the file Individual star records do not contain full positional coordinates instead they contain coordinates relative to the central position of the zone they occupy Thus when parsing star catalogues i
82. images do not have dimensions that are powers of 2 128 256 etc they are re sized when loaded to meet this requirement alpha ALPHA 0 is transparent default 1 is opaque ALPHA can be fractional Note that images are drawn in the order they were loaded i SCALE How large to draw the image In viewport coordinates at 1 the image is scaled to fit maximized in the viewport In horizontal coordinates this defines the maximum angular width of the image in degrees xpos X_POSITION Where to draw center of image 0 is center of viewport 1 is right edge of viewport ypos Y POSITION Where to draw center of image 0 is center of viewport 1 is top edge of viewport landscape load variable Load a landscape Arguments have same names and pos sible values as in a landscape ini file except that texture file names need to be specified in full including the path relative to the script Also add argument action load script action play end pause resume record cancelrecord Note that pause toggles playback If a script plays another script the first will terminate select If no arguments are supplied deselects current object Leaves constellation selection alone See deselect com mand constellation CONSTELLATION SHORT NAME 3 character abbreviation from constellationship fab case insensitive constellation star HP NUMBER Select the constellation which is made up by the specified star HP NUMBER Integer Hip
83. ing is on vacation If you can t get away from the cities easily make the most of it when you are away Wrap up warm The best observing conditions are the same conditions that make for cold nights even in the summer time Observing is not a strenuous physical activity so you will feel the cold a lot more than if you were walking around Wear a lot of warm clothing don t sit lie on the floor at least use a camping mat consider taking a deck chair and take a flask of hot drink Dark adaption The true majesty of the night sky only becomes apparent when the eye has had time to become accustomed to the dark This process known as dark adaption can take up to half and hour and as soon as the observer sees a bright light they must start the process over Red light doesn t compromise dark adaption as much as white light so use a red torch if possible and one that is as dim as you can manage with A single red LED light is ideal The Moon Unless you re particularly interested in observing the Moon on a given night it can be a nuisance it can be so bright as to make observation of dimmer objects such as nebulae impossible When planning what you want to observe take the phase and position of the Moon into account Of course Stellarium is the ideal tool for finding this out Averted vision A curious fact about the eye is that it is more sensitive to dim light towards the edge of the field of view If an object is slightly too dim to s
84. ion and other files in their personal user accounts In addition to the main search path Stellarium saves some files in other locations for example screens shots and recorded scripts The locations of the user directory installation directory screenshot save directory and script save directory vary according to the operating system and installation options used The following sections describe the locations for various operating systems 5 1 1 Windows installation directory By default this is C Program Files Stellarium although this can be adjusted during the installation process user directory This is the Stellarium sub folderin the Documents and Settings folder for the user account which is used to run Stellarium Depending on the version of Windows and its configuration this could be any of the following each of these is tried if it fails the next in the list if tried SUSERPROFILE Stellarium SHOMEDRIVE SHOMEPATHS Stellarium SHOME S Stellarium sSystemDrive Stellarium C Stellarium Thus on a typical Windows XP system with user Bob Dobbs the user directory will be The installation directory was referred to as the config root directory in previous versions of this guide 25 5 1 FILES AND DIRECTORIES CHAPTER 5 ADVANCED USE C Documents and Settings Bob Dobbs Stellarium screenshot save directory Screenshots will be saved to the Desktop script save directory Recorded scripts will be saved in the
85. ions are known a multiple star systems binary systems being the most common with two stars Multiple star systems are more common than solitary stars putting our Sun in the minority group Sometimes multiple stars orbit one another in a way that means one will periodically eclipse the other These eclipsing binaries or Algol variables 75 G 2 STARS APPENDIX G ASTRONOMICAL PHENOMENA Figure G 1 The constellation of Ursa Major G 2 2 Optical Doubles amp Optical Multiples Sometimes two or more stars appear to be very close to one another in the sky but in fact have great separation being aligned from the point of view of the observer but of different distances Such pairings are known as optical doubles and optical multiples G 2 3 Constellations The constellations are groupings of stars that are visually close to one another in the sky The actual groupings are fairly arbitrary different cultures have group stars together into different constellations In many cultures the various constellations have been associated with mythological entities As such people have often projected pictures into the skies as can be seen in figure G T which shows the constellation of Ursa Major On the left is a picture with the image of the mythical Great Bear on the right only a line art version is shown The seven bright stars of Ursa Major are widely recognised known variously as the plough the pan handle and the big dipper Th
86. is is the most complicated part of the process of generating the panorama I used two separate programs to do this Firstly I used Microsoft Paint which is part of the Windows operating system to cleanup and resize the pictures to 800x600 size and so make them easier to handle in the panorama program If you have prominent foreground items like posts wires etc that occur in adjacent pictures the panorama program will have difficulty in discerning them because of the 3D effect and may give double images I overcame this by painting out the offending item by cut and paste between the two pictures Quite easy with a little practice using the zoom in facility and I found the MSpaint program the easiest to do this in When I had my 14 processed pictures I inserted them into the panorama program I used a program called the Panorama Factory Version 1 6 is a freebee that works well and can be downloaded from the internet a Google search will find it I used version 3 4 that is better and cost about 40 off the Internet This program has many options and can be configured to suit most cameras and can make a seamless 360 panorama in barrel form that will take a highly trained eye to find where the joins occur The resulting panorama was then loaded into Paint and trimmed to a suitable size Mine ended up 4606 x 461 pixels I stretched the 4606 to 4610 pixels almost no distortion that would allow cutting into 10 461x461 pictures at a later date If the heig
87. is sub grouping is known as an asterism a distinct grouping of stars On the right the picture of the bear has been removed and only a constellation diagram remains Stellarium can draw both constellation diagrams and artistic representations of the con stellations Multiple sky cultures are supported Western Polynesian Egyptian and Chi nese constellations are available although at time of writing the non Western constellations are not complete and as yet there are no artistic representations of these sky cultures Aside from historical and mythological value to the modern astronomer the constella tions provide a way to segment the sky for the purposes of describing locations of objects indeed one of the first tasks for an amateur observer is learning the constellations the process of becoming familiar with the relative positions of the constellations at what time of year a constellation is visible and in which constellations observationally interesting objects reside Internationally astronomers have adopted the Western Greek Roman con stellations as a common system for segmenting the sky As such some formalisation has been adopted each constellation having a proper name which is in Latin and a three letter abbreviation of that name For example Ursa Major has the abbreviation UMa G 2 4 Star Names Stars can have many names The brighter stars often have common names relating to myth ical characters from the various traditi
88. it lt planet gt _special specific calculations for major bodies lighting Turn on or off lighting effects Specify the rotational period of the body in hours rot_obliquity float Angle between rotational axis and perpendicular to orbital plane in degrees Table 5 9 ssystem ini file format 39 5 12 TAKING SCREENSHOTS CHAPTER 5 ADVANCED USE data cities fab Each line is one record which describes a city which will appear on the map in the location tab of the configuration dialog Each record is TAB separated with the following fields 1 City name 2 State Province or lt gt for none spaces replaced with underscores Country Latitude Longitude Altitude Time zone Show at zoom level data constellations boundaries dat This file provides data necessary for Stellarium to draw the boundaries of he constellations stars name fab This file defines the Flamsteed designation for a star see section G 2 4 7 Each line of the file contains one record of two fields separated by the pipe character The first field is the Hipparcos catalogue number of the star the second is the Flamsteed designation e g 72370 Q_Aps Table 5 11 Configuration files 5 12 Taking Screenshots You can save what is on the screen to a file by pressing CTRL s Screenshots are taken in bmp format and have filenames something like this stellarium 000 bmp stellariuim 001 bmp the number increments to
89. ith y float This parameter controls the properties of the 1 spheric_mirror scaling factor float This parameter controls the properties of the localization sky_culture string sets the sky culture to use Valid val ues are defined in the second column of data skycultures fab Values western poly nesian egyptian chinese The sky culture affects the constellations localization sky_locale string Sets langauge used for names of objects in the sky e g planets The value is a short locale code e g en de en_GB localization app_locale string Sets langauge used for Stellarium s user in terface The value is a short locale code e g en de en_GB stars star_scale float multiplies the size of the stars Typical value ee stars star_mag_scale float multiplies the magnitude of the stars higher values mean stars appear brighter Typical value 1 3 stars star_twinkle_amount float sets the amount of twinkling Typical value fe ee eee stars max_mag_star_name float sets the magnitude of the stars whose labels pe ciu c stars flag star twinkle bool set to false to turn star twinkling off true to mM Im 00 0 stars flag point star bool set to false to draw stars at a size that corre sponds to their brightness When set to true all stars are drawn at single pixel size flag_help set to true to show help on start up 44 APPENDIX A CONFIGURATION FILE flag_show_topbar set to true
90. itled Dedications You must delete all sections Entitled Endorsements 6 COLLECTIONS OF DOCUMENTS You may make a collection consisting of the Document and other documents released under this License and replace the individual copies of this License in the various documents with a single copy that is included in the collection provided that you follow the tules of this License for verbatim copying of each of the documents in all other respects You may extract a single document from such a collection and distribute it individually under this License provided you insert a copy of this License into the extracted document and follow this License in all other respects regarding verbatim copying of that document 7 AGGREGATION WITH INDEPENDENT WORKS A compilation of the Document or its derivatives with other separate and independent documents or works in or on a volume of a storage or distribution medium is called an aggregate if the copyright resulting from the compilation is not used to limit the legal rights of the compilation s users beyond what the individual works permit When the Document is included in an aggregate this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document If the Cover Text requirement of section 3 is applicable to these copies of the Document then if the Document is less than one half of the entire aggregate the Document s Cover Texts may be placed
91. l planets are relatively small comparatively dense and have solid rocky surface Most of their mass is made from solid matter which is mostly rocky and or metal lic in nature G 4 2 Jovian Planets Jupiter Saturn Uranus and Neptune make up the Jovian planets They are much more massive than the terrestrial planets and do not have a solid surface Jupiter is the largest of all the planets with a mass over 300 times that of the Earth The Jovian planets do not have a solid surface the vast majority of their mass being in gaseous form although they may have rocky or metallic cores Because of this they have an average density which is much less than the terrestrial planets Saturn s mean density is only about 0 7 g cm it would float in water G 5 The Minor Planets As well as the Major Planets the solar system also contains innumerable smaller bodies in orbit around the Sun These are generally classed as the minor planets or planetoids and include asteroids and sometimes comets G 5 1 Asteroids Asteroids are celestial bodies orbiting the Sun in more or less regular orbits mostly between Mars and Jupiter They are generally rocky bodies like the inner terrestrial planets but of much smaller size There are countless in number ranging in size from about ten meters to thousands of kilometres Note that are time of writing Stellarium does not simulate asteroids G 5 2 Comets A comet is a small body in the solar system
92. ley 2005 5 Various Wikibooks Astronomy Wikimedia Foundation 97 Index Algol variables 75 altitude 35 67 altitude angle Andromeda angles 70 annual parallax 72 apparent magnitude 77 arc minutes arc second 69 arc seconds 70 asterism 76 asteroid B7 asteroids astro photography astrometry 75 astronomical unit 69 Atmosphere 23 atmosphere atmospheric effects 66 fog AU 69 auto completion 13 auto zoom 11 axis of rotation azimuth 67 angle 67 azimuth angle 67 azimuthal equidistant projection Barnard s Star 74 Bayer Johan 77 binaries binoculars 88 brightness brown dwarfs cardinal points 23 66 catalogue celestial equator 67 67 celestial pole 66 67 celestial sphere 56 66 67 70 711 75 Cepheid variable 80 Ceres clock 10 66 cluster 35 comet 37 82 85 Comet Halley common name common names config ini 27 configuration file 18 26123 constellation 11 Andromeda Aquarius 85 Canis Major 77 Cassiopeia DI diagram Orion 7 Ursa Major 76 constellation art constellations 26 76 coordinate system 67 crossbow 86 customising landscapes cylinder projection 21 cylindrical equidistant projection 21 date 9 18 BA Dec 67 declination 67 72 disk viewport display display resolution 22 dwarf planet 37 81 dwarf stars 78 Earth 70
93. lluminated surface on the edge Less than half the disc is illuminated but Waxing Crescent oe more is illuminated each night Hat Diarier Approximately half the disc is illuminated and increasing each night Waxine Gibb More than half of the disc is illuminated and still increasing each night but this gets less each night minated and this gets less each night Table G 6 Phases of the moon Full Moon The whole disc of the moon is illuminated than half of the disc is illuminated Waning Gibbous but the amount gets smaller each night G 2 6 Variables Most stars are of nearly constant luminosity The Sun is a good example of one which goes through relatively little variation in brightness usually about 0 1 over an 11 year solar cycle Many stars however undergo significant variations in luminosity and these are known as variable stars There are many types of variable stars falling into two categories intrinsic and extrinsic Intrinsic variables are stars which have intrinsic variations in brightness that is the star itself gets brighter and dimmer There are several types of intrinsic variables probably the best known and more important of which is the Cepheid variable whose luminosity is related to the period with which it s brightness varies Since the luminosity and therefore absolute magnitude can be calculated Cepheid variables may be used to determine the distance of the star when
94. mensions which are integer powers of two i e 1 2 4 8 16 32 64 128 256 512 1024 pixels along each side If this requirement is not met your textures may not be visible or graphics performance may be seriously impacted PNG or JPG formats are both supported 5 8 4 Modifying ngc2000 dat Each deep sky image has one line in the ngc2000 dat file in the nebulae default directory where is either the installatiom directory or the user directory The file is a plain ASCII file and may be edited with a normal text editor Each line contains one record each record consisting of the following fields Describes the E I IO type I Index Catalogue anything else means NGC p p nione number 9038 Sets nType Possible values NEB OC OC NEB GC Gb NEB Nb NEB PN P Poxk or pre FRERE C N NEB CN NEB UNKNOWN 12 9 Right ascention hour right ascention minute Declination degree sign f Declination degree Declination minute 35 5 8 ADDING NEBULAE IMAGES CHAPTER 5 ADVANCED USE am s 9t Magnitude SS 5 8 2 Modifying ngc2000names dat Each line in the ngc2000names dat file contains one record A record relates an extended object catalogue number from ngc2000 dat with a name A single catalogue number may have more than one record in this file The record structure is as follows 35 35s Name Note that messier numbers should be the
95. minosities where an object with twice the Sun s luminosity is considered to have two solar luminosities and so on Luminosity is related to absolute magnitude F 4 Precession As the Earth orbits the Sun throughout the year the axis of rotation the line running through the rotational poles of the Earth seems to point towards the same position on the celestial sphere as can be seen in figure E 4 The angle between the axis of rotation and the perpendicular of the orbital plane is called the obliquity of the ecliptic It is 23 27 71 E5 PARALLAX APPENDIX ASTRONOMICAL CONCEPTS Figure E 4 Obliquity of the Ecliptic Observed over very long periods of time the direction the axis of rotation points does actually change The angle between the axis of rotation and the orbital plane stays constant but the direction the axis points the position of the celestial pole transcribes a circle on the stars in the celestial sphere This process is called precession The motion is similar to the way in which a gyroscope slowly twists as figure E 5 illustrates Precession is a slow process The axis of rotation twists through a full 360 about once every 28 000 years Precession has some important implications 1 RA Dec coordinates change over time albeit slowly Measurements of the positions of stars recorded using RA Dec coordinates must also include a date for those coor dinates 2 Polaris the pole star won t stay a good indicato
96. n apparently large celestial body planet moon etc moves between the observer that s you and a more distant object the more distant object being eclipsed by the nearer one G 10 1 Solar Eclipses Solar eclipses occur when our Moon moves between the Earth and the Sun This happens when the inclined orbit of the Moon causes its path to cross our line of sight to the Sun In essence it is the observer falling under the shadow of the moon There are three types of solar eclipses Partial The Moon only covers part of the Sun s surface Total The Moon completely obscures the Sun s surface Annular The Moon is at aphelion furthest from Earth in its elliptic orbit and its disc is too small to completely cover the Sun In this case most of the Sun s disc is obscured all except a thin ring around the edge G 10 2 Lunar Eclipses Lunar eclipses occur when the Earth moves between the Sun and the Moon and the Moon is in the Earth s shadow They occur under the same basic conditions as the solar eclipse but can occur more often because the Earth s shadow is so much larger than the Moon s Total lunar eclipses are more noticeable than partial eclipses because the Moon moves fully into the Earth s shadow and there is very noticeable darkening However the Earth s atmosphere refracts light bends it in such a way that some sunlight can still fall on the Moon s surface even during total eclipses In this case there is often a m
97. n the sky as dim fuzzy blobs Only four are normally visible to the naked eye The Andromeda galaxy M31 visible in the Northern hemisphere the two Magellanic clouds visible in the Southern hemisphere and the home galaxy Milky Way visible in parts from north and south under dark skies There are thought to be billions of galaxies in the universe comprised of an unimagin ably large number of stars The vast majority of galaxies are so far away that they are very dim and cannot be seen without large telescopes but there are dozens of galaxies which may be observed in medium to large sized amateur instruments Stellarium includes images of many galax ies including the Andromeda galaxy M31 the Pinwheel Galaxy M101 the Sombrero Galaxy M104 and many others Astronomers classify galaxies according to their appearance Some classifications in clude spiral galaxies elliptical galaxies lenticular galaxies and irregular galaxies G 7 The Milky Way It s a little hard to work out what our galaxy would look like from far away because when we look up at the night sky we are seeing it from the inside All the stars we can see are part of the Milky Way and we can see them in every direction However there is some structure There is a higher density of stars in particular places There is a band of very dense stars running right round the sky in huge irregular stripe Most of these stars are very dim but the overall effect is that on very
98. n three spaces then the number NEM RT 5 u Cmiememmie If an object has more than one record in the ngc2000names dat file the last record in the file will be used for the nebula label 5 8 3 Modifying nebula textures fab Each line in the nebula textures fab file is one record Records are whitespace sepa rated so there are not strictly any offsets for particlar fields Note that filenames may not contains spaces and are case sensitive Lines with the character in the first column are considered to be comments and will be ignored Empty lines are ignored The record format is as follows Texture angular size Texture rotation Texture filename including png extension 5 8 4 Editing Image Files Images files should be copied to the nebulae lt set gt directory where set is the name of the nebula texture set to be modified which is usually default Images should be in PNG or JPEG format Images should have an aspect ratio of 1 i e it should be square and should have a width amp height of 2 pixels where n is a positive integer i e 2 4 8 16 32 64 128 256 512 and so on Black is interpretted as being 100 transparent Ensure that the background of the image is totally black i e has RGB values 0 0 0 and not just nearly black since this can cause an ugly square around the object There is a lot of software which may be used to create modify PNG and JPEG images The
99. nfiguration file A complete list of configuration file values may be found in appendix A 5 2 1 Setting Your Location Precisely The user interface for setting the observer s longitude and latitude isn t very precise For users with a penchant for accuracy satisfaction may be achieved by editing the values in the configuration file like this init location name Widdringon latitude 55 14 30 00 longitude 01 37 6 00 altitude 53 The values for longitude and latitude are positive for North and East negative for South and West The format of the number is in degrees minutes and seconds The value for the altitude is in meters t is possible to specify a different name for the main configuration file using the config file command line option See section 5 3 for details 27 5 3 COMMAND LINE OPTIONS CHAPTER 5 ADVANCED USE 5 2 2 Setting the Display Resolution If your screen resolution is not listed in the video tab of the configuration window you may edit the configuration file to select it It is also possible to specify how Stellarium should start in windowed or full screen mode video fullscreen true screen_w 1680 screen_h 1050 5 2 3 Enabling the Script Bar Individual script commands see section 5 5 may be entered and executed interactively using a feature called the script bar This feature is not enabled by default but you can enable it by altering the configuration file gui fla
100. noculars Under good conditions it constellation of Cassiopeia appears as a large fuzzy patch of light It is a galaxy containing billions of stars whose distance is roughly three million light years from Earth The Garnet Star Mu Cephei Variable Star 4 25 Avg Cephius lies above the W shape A supergiant of spectral class M with of Cassiopeia The Garnet Star a strong red colour Given it s name by lies slightly to one side of a point Sir William Herschel in the 18th century half way between 5 Cephei and 21 the colour is striking in comparison to it s Cephei blue white neighbours 4 and 5 Lyrae Epsilon Lyrae Double Star 47 Look near to Vega Alpha Lyrae In binoculars epsilon Lyrae is resolved into one of the brightest stars in the sky two separate stars Remarkably each of these is also a double star although this will only be seen with a telescope and all four stars form a physical system 88 APPENDIX H SKY GUIDE Shean Other Names M13 Hercules Cluster Globular 5 8 Located approximately of the way This cluster of hundreds of thousands of Cluster along a line from 40 to 44 Herculis mature stars that appears as a circular cloud using the naked eye or binoculars a large telescope is required to resolve in dividual stars Oddly the cluster appears to contain one young star and several areas that are almost devoid of stars M45 The Pleiades The Open Cluster 1 2 Avg Lies a little under halfway between
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102. ntrol various aspects of Stellarium See section 3 T 8 for a complete list of key bindings 3 1 6 Information Window Inform Stellarium 0 8 0 August 2005 software y s of the GNU Fo TY or FITNESS FOR A eral Public Figure 3 5 The information window Pressing the i key on the keyboard toggles the display of the information window This displays the version number of Stellarium and some information about the project 14 3 1 TOUR CHAPTER 3 INTERFACE GUIDE 3 1 7 The Text Menu As well as the regular key bindings and the tool bars Stellarium has another method for interaction with the user the Text Menu or Text User Interface TUI The TUI is activated using the m key and is navigated using the cursor keys Table 3 8 shows the commands that are available from the TUI menu Many of the options in the TUI menu are duplicated elsewhere in the interface For example the ability to set the maximum star magnitude to label is also accessible via the configuration window see section 4 4 3 1 8 Other Keyboard Commands As mentioned in section 3 1 5 not all keys are documented in the Help window Some features of Stellarium are only available via the keyboard and are not easy to discover Here is a full listing of Stellarium s key bindings C qee RN e nm LLL em RR pe eme Toggle full screen mode not available on some architectures Toggl
103. nts amp tips 30 recording 29 seconds of arc 70 shooting stars sidereal day 69 100 INDEX skins 20 sky culture sky cultures SoL 75 solar day 69 solar system 35 69 spectra spectral type speed of light 69 spherical BI spiral galaxies 83 star dog star the 77 Sirius star catalogue star cluster 35 star clusters 85 star data records Stars stars 18 BI 60 G72 73 Betelgeuse 77 Polaris 72 Proxima Centuri 74 75 Sadalmelik 85 Sirius 77 stellar parallax 72 stereographic projection 21 sub system Sun 66 69 7T 74 75 81 super giants supernova remnant system clock IO telescope control 40 telescope server terrestrial planets 81 text menu 15 15 18 29 texture files time 9 T0 T8 0 67 time rate time zone T8 28 tool bar main 9 11 18 23 67 time 9 TUL 131 18 twinkle 23 Tycho catalogue units 69 Uranus 82 User Directory user directory 25RA BO INDEX variable stars 80 Algol 75 vector 47 56 Venus viewport 21 22 viewport distorter 22 visual effects white dwarfs 78 window configuration 15 18 landscape landscapes tab 20 B1 33 language tab 22 37 location tab 18 0 66 67 rendering tab 22 video tab 21 28 find 113 help 14 5 information 14 search 13 windowed mode zenith BI 66 67 zones zo
104. o copy and distribute verbatim copies of this license document but changing it is not allowed 0 PREAMBLE The purpose of this License is to make a manual textbook or other functional and useful document free in the sense of freedom to assure everyone the effective freedom to copy and redistribute it with or without modifying it either commercially or noncommercially Secondarily this License preserves for the author and publisher a way to get credit for their work while not being considered responsible for modifications made by others This License is a kind of copyleft which means that derivative works of the document must themselves be free in the same sense It complements the GNU General Public License which is a copyleft license designed for free software We have designed this License in order to use it for manuals for free software because free software needs free documentation a free program should come with manuals providing the same freedoms that the software does But this License is not limited to software manuals it can be used for any textual work regardless of subject matter or whether it is published as a printed book We recommend this License principally for works whose purpose is instruction or reference 1 APPLICABILITY AND DEFINITIONS This License applies to any manual or other work in any medium that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License
105. olution on the sky isn t significantly worse for the type 1 and 2 records in practice 58 D 2 STAR CATALOGUE FILE FORMAT APPENDIX D STAR CATALOGUE Magic 0 int 4 The magic number which identifies the file as a star catalogue 0xde0955a3 Data Type 4 int 4 This describes the type of the file which defines the size and structure of the Star Data record for the file Major Version int 4 The file format major version ped lt E e Minor Version 12 int 4 The file format minor version rem Level 16 int 4 Sets the level of sub division of the geodesic sphere used to create the zones 0 means an icosahedron 20 sizes subsequent levels of sub division lead to numbers of zones as described in section D T i Magnitude Minimum 20 int 4 The low bound of the magnitude scale for values in this file Note that this is still an integer in Stellarium s own internal representation Magnitude Range 24 int 4 The range of magnitudes expressed Ron Magnitude Steps 28 int 4 The number of steps used to dE T DIES Table D 6 Header Record num stars in zone 0 0 int 4 The number of records in this file which are in zone 0 num stars in zone 1 4 int 4 The number of records is this file which are in zone 1 num stars in zone n 4n int 4 The number of records is this file which in zone n Table D 8 Zones section 59 D 2 STAR CATALOGUE FILE FORMAT APPENDIX D STAR CATALOGUE Name ana m char hip Hippa
106. om 101 INDEX
107. on covers that bracket the Document within the aggregate or the electronic equivalent of covers if the Document is in electronic form Otherwise they must appear on printed covers that bracket the whole aggregate 8 TRANSLATION Translation is considered a kind of modification so you may distribute translations of the Document under the terms of section 4 Replacing Invariant Sections with translations requires special permission from their copyright holders but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections You may include a translation of this License and all the license notices in the Document and any Warranty Disclaimers provided that you also include the original English version of this License and the original versions of those notices and disclaimers In case of a disagreement between the translation and the original version of this License or a notice or disclaimer the original version will prevail If a section in the Document is Entitled Acknowledgements Dedications or History the requirement section 4 to Preserve its Title section 1 will typically require changing the actual title 9 TERMINATION You may not copy modify sublicense or distribute the Document except as expressly provided for under this License Any other attempt to copy modify sublicense or distribute the Document is void and will automatically terminate your rights under
108. ons For example the brightest star in the sky Sirius Contributions of artwork for these sky cultures would be very welcome post in the forums if you can help 76 G 2 STARS APPENDIX G ASTRONOMICAL PHENOMENA Fomalhaut a PsA Magnitude 1 19 RADE 22h58m00s 29 35 16 AZA 175 05 48 11 39 21 Distance 25 07 Light Years Cat HP 113368 Spectral Type A Figure G 2 Stellarium displaying information about a star is also known as The Dog Star the name Canis Major the constellation Sirius is found in is Latin for The Great Dog There are several more formal naming conventions that are in common use G 2 4 1 Bayer Designation German astronomer Johan Bayer devised one such system in the 16 17th century His scheme names the stars according to the constellation in which they lie prefixed by a lower case Greek letter starting at for the brightest star in the constellation and proceeding with B y in descending order of apparent magnitude For example such a Bayer Designation for Sirius is 0 Canis Majoris note that the genitive form of the constellation name is used There are some exceptions to the descending magnitude ordering and some multiple stars both real and optical are named with a numerical superscript after the Greek letter e g x n Orionis 2 4 2 Flamsteed Designation English astronomer John Flamsteed numbered stars in each constellation in order of in creasing right as
109. ound from a point in the sky known as the first point of Aries in the same way that longitude is measured around the Earth from Greenwich Figure E2 illustrates RA Dec coordinates Unlike Altitude Azimuth coordinates RA Dec coordinates of a star do not change if the Observer changes latitude and do not change over the course of the day due to the rotation of the Earth the story is complicated a little by precession and parallax see sections E 4 and E S respectively for details RA Dec coordinates are frequently used in star catalogues such as the Hipparcos catalogue Stellarium can draw grid lines for RA Dec coordinates Use the button on the main tool bar to activate this grid or press the e key Units F 3 1 Distance As Douglas Adams pointed out in the Hitchhiker s Guide to the Galaxy I Space is big You just won t believe how vastly hugely mind bogglingly big itis I mean you may think it s a long way down the road to the chemist s but that s just peanuts to space M Astronomers use a variety of units for distance that make sense in the context of the mind boggling vastness of space Astronomical Unit AU This is the mean Earth Sun distance Roughly 150 million kilo metres 1 49598 x 105km The AU is used mainly when discussing the solar system for example the distance of various planets from the Sun Light year A light year is not as some people believe a measure of time It is the dis tance that light tr
110. oving Around the Sky Pan the view left right up and down Backslash Auto zoom out to original field of view and viewing direction Select an object in the sky Centre view on selected object Forward slash Auto zoom in to selected object Table 3 4 Controls to do with movement 10 3 1 TOUR CHAPTER 3 INTERFACE GUIDE As well as travelling through time Stellarium lets to look around the sky freely and zoom in and out There are several ways to accomplish this listed in table 3 4 Let s try it Use the cursors to move around left right up and down Zoom in a little using the Page Up key and back out again using the Page Down Press the backslash key and see how Stellarium returns to the original field of view how zoomed in the view is and direction of view It s also possible to move around using the mouse If you left click and drag somewhere on the sky you can pull the view around Another method of moving is to select some object in the sky left click on the object and press the Space key to centre the view on that object Similarly selecting an object and pressing the forward slash key will centre on the object and zoom right in on it The forward slash and backslash keys auto zoom in an out to different levels depending on what is selected If the object selected is a planet or moon in a sub system with a lot of moons e g Jupiter the initial zoom in will go to an intermediate level where the whole sub
111. parcos catalogue number 53 APPENDIX B SCRIPTING COMMANDS Camana Argument Nares Anginen Values pointer on 1 off 0 Whether to draw the highlighting pointer around the se lected object Default is on atmosphere fade duration SECONDS Number of seconds it takes for atmosphere toggle to com plete SECONDS Used for auto constellation_art_intensity 0 0 1 0 Floating point number between 0 and 1 constellation_art_fade_duration SECONDS Number of seconds it takes for constellation art toggle to complete home_planet PLANET_NAME The planet name comes from the ssystem ini file It is case sensitive max_mag_nebula_name MAGNITUDE Floating point apparent magnitude value Only label neb ulas brighter than this max_mag_star_name MAGNITUDE Floating point apparent magnitude value Only label neb ulas brighter than this ae eet O e e 1 1 ee wait SECONDS Only useful in scripts SECONDS can be fractional zoom auto in initial out initial returns to configured initial fov and viewing di rection duration SECONDS Not used with delta_fov 54 Appendix C Precision Stellarium uses the VSOP87 method to calculate the variation in position of the planets over time As with other methods the precision of the calculations vary according to the planet and the time for which one makes the calculation Reasons for these inaccuracies include the fact that the motion of the planet isn t a
112. r a landscape should by put in the same directory as the 1andscape ini file although if they are not found there they will be searched for in the textures directory allowing shared files for common textures such as the fog texture For example the Moon landscape that is provided with Stellarium has the following files landscapes moon landscape ini landscapes moon apollol7 png The landscsape ini file must contain a section called landscape which contains the details necessary to render the landscape which vary depending on the type of the landscape There is also an optional location section which is used to tell Stellarium where the landscape is in the solar system If the location section exists Stellarium can automatically adjust the location of the observer to match the landscape 5 7 1 Single Fish eye Method The 7rees landscape that is provided with Stellarium is an example of the single fish eye method and provides a good illustration The centre of the image is the spot directly above the observer the zenith The point below the observer the nadir becomes a circle that just touches the edges of the image The remaining areas of the image the rounded corners are not used The image file should be saved in PNG format with alpha transparency Wherever the image is transparent is where Stellarium will render the sky The 1andscape ini file for a fish eye type landscape looks like this this example if for t
113. r and type in the new value Using the configuration window for this presently requires a lot of clicks on the very small up and down arrows which is time consuming and irritating The lack of flexibility of the current GUI toolkit is something which we are aware of and will remedy within the next few releases Actually there are four methods you can also edit the configuration file This is useful if you want to be more precise than is possible with the existing user interface See section 5 2 1 for more details 5If you don t know your longitude and latitude you may find this site helpful 18 4 2 SETTING YOUR LOCATION CHAPTER 4 CONFIGURATION Figure 4 1 Configuration window Date amp Time tab Figure 4 2 Configuration window location tab 19 4 3 SETTING THE LANDSCAPE GRAPHICS CHAPTER 4 CONFIGURATION 3 In the Landscape tab of the configuration window check the Setting landscape up dates the location box and select a new landscape The obserever location will be set to the location for that landscape Once you re happy that the location is set correctly click on the Save Location button and close the configuration window 4 3 Setting the Landscape Graphics Stellarium has several horizon graphics or landscapes These may be changed by choosing the options under the Landscapes tab in the configuration window Configuration Landscapes Garching Author Fabien Chereau Guereins Hurricane Moon
114. r of the location of the Northern celestial pole In 14 000 years time Polaris will be nearly 47 away from the celestial pole F 5 Parallax Parallax is the change of angular position of two stationary points relative to each other as seen by an observer due to the motion of said observer Or more simply put it is the apparent shift of an object against a background due to a change in observer position This can be demonstrated by holding ones thumb up at arm s length Closing one eye note the position of the thumb against the background After swapping which eye is open without moving the thumb appears to be in a different position against the background A similar thing happens due to the Earth s motion around the Sun Nearby stars appear to move against more distant background stars as illustrated in figure E 6 The movement of nearby stars against the background is called stellar parallax or annual parallax Since we know the distance the radius of the Earth s orbit around the Sun from other methods we can use simple geometry to calculate the distance of the nearby star if we measure annual parallax In figure 6 the annual parallax p is half the angular distance between the apparent positions of the nearby star The distance of the nearby object is d Astronomers use a unit 72 E5 PARALLAX APPENDIX E ASTRONOMICAL CONCEPTS Polaris X geer Rad a a a eH d 2 ecliptic South pole 23 27 Figure F 5 Pre
115. rcos catalogue Hipparcos catalogue number component_ids This is an index to an array of catalogue number suffixes The list is read from the stars hip component ids cat file The value of this field turns out to be the line number in the file 1 This is the position of the star relative to the central point in the star s zone in axis 1 This is the position of the star relative to the central point in the ME unsigned char This is the PTE level in B V colour This value refers to one of 256 discrete steps in the magnitude range for the file B an e V I colour This value refers to one of 256 discrete steps in the This is the magnitude level in the unsigned short int magnitude range for the file This is the index in an array of spectral type descriptions which is taken from the file stars hip sp cat the index corresponds to the line number in the file 1 This is the e proper motion of the This is the motion of the This is the of the star To get the actual value divide by 10000 Table D 10 Star Data Record Type 0 60 D 2 STAR CATALOGUE FILE FORMAT APPENDIX D STAR CATALOGUE x0 0 int 20 bits This is the position of the star relative to the central point in the star s zone in axis 1 xl 20 bits int 20 bits This is the position of the star relative to the central point in the star s zone in axis 2 40 bits bits This is the proper motion of the ee ue 54 bits bits
116. re is the maxi chart_color mum e g 0 1 0 1 0 for white color nebula_label_color float R G B sets the colour of the nebula labels in RGB night_color values where 1 is the maximum is the chart_color maximum e g 0 1 0 1 0 for white color nebula_circle_color float R G B sets the colour of the circle of the nebula la night_color bels in RGB values where is the maxi chart_color mum e g 0 1 0 1 0 for white color star_label_color float R G B sets the colour of the star labels in RGB night_color values where is the maximum e g chart_color 1 0 1 0 1 0 for white color star_circle_color float R G B sets the colour of the circle of the star labels night_color in RGB values where is the maximum chart_color e g 1 0 1 0 1 0 for white color cardinal_color float R G B sets the colour of the cardinal points in night_color RGB values where is the maximum e g chart_color 1 0 1 0 1 0 for white color planet_names_color float R G B sets the colour of the planet names in RGB night_color values where is the maximum e g chart_color 1 0 1 0 1 0 for white color planet_orbits_color float R G B sets the colour of the planet orbits in RGB night_color values where is the maximum e g chart_color 1 0 1 0 1 0 for white color object_trails_color float R G B sets the colour of the object trails in RGB night_color values where is the maximum e g chart_color 1 0 1
117. remnant and the Dumbbell Nebula M27 which is a planetary nebula G 9 Meteoroids These objects are small pieces of space debris left over from the early days of the solar system that orbit the Sun They come in a variety of shapes sizes an compositions ranging from microscopic dust particles up to about ten meters across Sometimes these objects collide with the Earth The closing speed of these collisions is generally extremely high tens or kilometres per second When such an object ploughs 83 G 10 ECLIPSES APPENDIX G ASTRONOMICAL PHENOMENA through the Earth s atmosphere a large amount of kinetic energy is converted into heat and light and a visible flash or streak can often be seen with the naked eye Even the smallest particles can cause these events which are commonly known as shooting stars While smaller objects tend to burn up in the atmosphere larger denser objects can penetrate the atmosphere and strike the surface of the planet sometimes leaving meteor craters Sometimes the angle of the collision means that larger objects pass through the atmo sphere but do not strike the Earth When this happens spectacular fireballs are sometimes seen Meteoroids is the name given to such objects when they are floating in space A Meteor is the name given to the visible atmospheric phenomenon Meteorites is the name given to objects that penetrate the atmosphere and land on the surface G 10 Eclipses Eclipses occur when a
118. s Catalogue 120 000 stars with 1 milli arc second level astrometry and the final Tycho Catalogue more than one million stars with 20 30 milli arc second astrometry and two colour photometry were completed in August 1996 The catalogues were published by ESA in June 1997 The Hipparcos and Tycho data have been used to create the Millennium Star Atlas an all sky atlas of one million stars to visual magnitude 11 from the Hipparcos and Tycho Catalogues and 10 000 non stellar objects included to complement the catalogue data There were questions over whether Hipparcos has a systematic error of about milli arc second in at least some parts of the sky The value determined by Hipparcos for the distance to the Pleiades is about 10 less than the value obtained by some other methods By early 2004 the controversy remained unresolved Stellarium uses the Hipparcos Catalogue for star data as well as having traditional names for many of the brighter stars The stars tab of the search window allows for search ing based on a Hipparcos Catalogue number as well as traditional names e g the star Sadalmelik in the constellation of Aquarius can be found by searching for the name or it s Hipparcos number 109074 G 11 2 The Messier Objects The Messier objects are a set of astronomical objects catalogued by Charles Messier in his catalogue of Nebulae and Star Clusters first published in 1774 The original motivation behind the catalogue was that Messier
119. s at the bottom of the screen 5 Now increase the time rate Press 1 1 1 1 this should set the time rate so the stars can be seen to rotate around a point in the sky about once every ten seconds If you watch Stellarium s clock you ll see this is the time it takes for one day to pass as this accelerated rate The point which the stars appear to move around is one of the Celestial Poles The apparent movement of the stars is due to the rotation of the Earth The location of the observer on the surface of the Earth affects how she perceives the motion of the stars To an observer standing at Earth s North Pole the stars all seem to rotate around the zenith the point directly directly upward As the observer moves South towards the equator the 66 E2 COORDINATE SYSTEMS APPENDIX ASTRONOMICAL CONCEPTS location of the celestial pole moves down towards the horizon At the Earth s equator the North celestial pole appears to be on the Northern horizon Similarly observers in the Southern hemisphere see the Southern celestial pole at the zenith when they are at the South pole and it moves to the horizon as the observer travels towards the equator 1 Leave time moving on nice and fast and open the configuration window Go to the location tab and click on the map right at the top i e set your location to the North pole See how the stars rotate around a point right at the top of the screen With the field of view set to 90
120. s disclaiming warranties any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License 2 VERBATIM COPYING You may copy and distribute the Document in any medium either commercially or noncommercially provided that this License the copyright notices and the license notice saying this License applies to the Document are reproduced in all copies and that you add no other conditions whatsoever to those of this License You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute However you may accept compensation in exchange for copies If you distribute a large enough number of copies you must also follow the conditions in section 3 You may also lend copies under the same conditions stated above and you may publicly display copies 3 COPYING IN QUANTITY If you publish printed copies or copies in media that commonly have printed covers of the Document numbering more than 100 and the Document s license notice requires Cover Texts you must enclose the copies in covers that carry clearly and legibly all these Cover Texts Front Cover Texts on the front cover and Back Cover Texts on the back cover Both covers must also clearly and legibly identify you as the publisher of these copies The front cover must present the full title with all words of the title equally prominent and visible You may add other material on t
121. s of arc Finer grades of precision are usually expressed using the SI prefixes with arc seconds e g milli arc seconds one milli arc second is one thousandth of an arc second F3 3 1 Notation Degrees are denoted using the symbol after a number Minutes of arc are denoted with a and seconds of arc are denoted using Angles are frequently given in two formats 1 DMS format degrees minutes and seconds For example 90 5 2 When more precision is required the seconds component may include a decimal part for exam ple 90 5712 432 2 Decimal degrees for example 90 2533 70 E4 PRECESSION APPENDIX ASTRONOMICAL CONCEPTS Sirius the brightest star 1 A Venus at brightest 4 Full Moon at brightest 12 6 Table 2 Magnitudes of well known objects F 3 4 The Magnitude Scale When astronomers talk about magnitude they are referring to the brightness of an object How bright an object appears to be depends on how much light it s giving out and how far it is from the observer Astronomers separate these factors by using two measures absolute magnitude M which is a measure of how much light is being given out by an object and apparent magnitude m which is how bright something appears to be in the sky For example consider two 100 watt lamps one which is a few meters away and one which is a kilometre away Both give out the same amount of light they have the same absolute magnitude Howe
122. s predictable as Newtonian mechanics would have us believe As far as Stellarium is concerned the user should bear in mind the following properties of the VSOP87 method Mercury Venus Precision is 1 arc second from 2000 B C 6000 A D Earth Moon barycenter Mars Precision is 1 arc second from 4000 B C 8000 A D Pluto Pluto s position is valid from 1885 A D 2099 A D Earth s Moon ELP2000 82B Unsure about interval of validity or precision at time of writing Possibly valid from 1828 A D to 2047 A D Galilean satellites Valid from 500 A D 3500 A D Uranus Neptune 55 Appendix D Star Catalogue This document describes how Stellarium records it s star catalogues and the related file formats D 1 Stellarium s Sky Model D 1 1 Zones The celestial sphere is split into zones which correspond to the triangular faces of a geodesic sphere The number of zones faces depends on the level of sub division of this sphere The lowest level 0 is an icosahedron 20 faces subsequent levels L of sub division give the number of zones n as n 20 4 Stellarium uses levels 0 to 7 in the existing star catalogues Star Data Records contain the position of a star as an offset from the central position of the zone in which that star is located thus it is necessary to determine the vector from the observer to the centre of a zone and add the star s offsets to find the absolute position of the star on the celest
123. so stars whose absolute magnitude is very low regardless of the spectral class These are known as dwarf stars among them white dwarfs and brown dwarfs A luminosity class is an indication of the type of star whether it is main sequence a giant or a dwarf Luminosity classes are denoted by a number in roman numerals as described in table G 4 Sub dwarfs White dwarfs Table G 4 Luminosity Class Plotting the luminosity of stars against their spectral type surface temperature gives a diagram called a Hertzsprung Russell diagram after the two astronomers Ejnar Hertzsprung and Henry Norris Russell who devised it A slight variation of this is see in figure G 3 which is technically a colour magnitude plot common aide to memory for the letters used in spectral types is the mnemonic Oh Be A Fine Girl Kiss 78 G 2 STARS APPENDIX G ASTRONOMICAL PHENOMENA Spectral Class O B A F 3 K M 10 30000K 10000K 7500K 6000K 5000K 4000 3000K Temperature 100 000 la Supergiants 10 000 Ib 5 P II Bright 1 000 98 Giants Ill Giants 2h Qu 100 0 30 ec E o 10 gt IV Subgiants 2H u Oo II Ee 1 5 34 V Main Sequence 0 1 0 01 10 0 001 0 0001 15 White Dwarfs 0 00001 0 0 0 5 1 0 1 5 2 0 Colour B V Figure G 3 Plot of star colour vs magnitude 79 G 3 OUR MOON APPENDIX G ASTRONOMICAL PHENOMENA The moon s disc is fully in shadow or there New Moon is just a slither of i
124. system should be visible A second zoom will go to the full zoom level on the selected object Similarly if you are fully zoomed in on a moon of Jupiter the first auto zoom out will go to the sub system zoom level Subsequent auto zoom out will fully zoom out and return the initial direction of view For objects that are not part of a sub system the initial auto zoom in will zoom right in on the selected object the exact field of view depending on the size type of the selected object and the initial auto zoom out will return to the initial FOV and direction of view 3 1 3 Main Tool bar 21 17 11 Stellarium 0 8 0 Earth Paris 83m FOV 50 FPS 34 79 Figure 3 2 Screenshot showing off some of Stellarium s visual effects Stellarium can do a whole lot more than just draw the stars Figure shows some of Stellarium s visual effects including constellation line and boundry drawing constellation art planet hints and atmospheric fogging around the bright Moon The controls main tool 11 3 1 TOUR CHAPTER 3 INTERFACE GUIDE bar provides a mechanism for turning on and off the visual effects Table 3 6 describes the operations of buttons on the main tool bar and gives their keyboard shortcuts c Draws the constellation lines v Draws the name of the constellations Constellation Art Superimposes artistic representations of the constellations over the stars Azimuth Grid Draws grid lines for the Alt Azi coordinate system Equa
125. t a mask around the whole picture Next I selected the brush tool and toggled the foreground to white and painted the whole channel white using a very large brush size 445 pixels 3 Next I turned the alpha channel off and selected the other channels to get the orig inal picture I got rid of the full mask that I had forgotten to remove by selecting Step backwards from the edit menu I first tried the magnetic loop tool to select the 63 APPENDIX E CREATING A PERSONALISED LANDSCAPE FOR STELLARIUM sections for a mask but it was too fiddly for me I then used the magic wand tool to select the sky sections bit by bit zoom in on the image to see what you are doing this would have been easy if the sky had been cloudless because colour match does this selection I cut each selection out It took about an hour to remove all the sky because it was cloudy and leave just the skyline image as a suitable mask Clicking the magic wand in the sky area when all the sky has been removed will show an out line mask of the removed sky Zoom in and carefully check the whole area to make sure there is no sky left Leave this mask there Re select the alpha channel and turn the other channels off The alpha channel will be visible and the mask should be showing Re select Edit in Quick mask mode and then Edit in standard mode to edit Select the brush tool and toggle to the black foreground Fill in the masked area with a large brush size The colour black
126. t is in the sky it s light is scattered by the atmosphere to such an extent that almost all other objects in the sky are rendered invisible The Sun is a star like many others but it is much closer to the Earth at approximately 150 million kilometres The next nearest star Proxima Centuri is approximately 260 000 times further away from us than the Sun The Sun is also known as Sol it s Latin name Over the course of a year the Sun appears to move round the celestial sphere in a great circle known as the ecliptic Stellarium can draw the ecliptic on the sky To toggle drawing of the ecliptic press the 4 or key WARNING Looking at the Sun can permanently damage the eye Never look at the Sun without using the proper filters By far the safest way to observe the Sun it to look at it on a computer screen courtesy of Stellarium G 2 Stars The Sun is just one of billions of stars Even though many stars have a much greater ab solute magnitude than the Sun the give out more light they have an enormously smaller apparent magnitude due to their large distance Stars have a variety of forms different sizes brightnesses temperatures and colours Measuring the position distance and at tributes of the stars is known as astrometry and is a major part of observational astronomy G 2 1 Multiple Star Systems Many stars have a stellar companions As many as six stars can be found orbiting one another in close association Such associat
127. t is necessary to know about the zone model to be able to extract positional data File Data Type Data Record Geodesic Records Notes Size Level Daneo oa 2 lsons 6 27730241 NOMAD Table D 2 Stellarium s star catalogue files For a given catalogue file there may be one of three formats for the actual star data The variation comes from the source of the data the larger catalogues of fainter stars providing less data per star than the brighter star catalogues See tables D 2Jand for details D 2 2 File Sections The catalogue files are split into three main sections as described in table D 4 57 D 2 STAR CATALOGUE FILE FORMAT APPENDIX D STAR CATALOGUE File Header Contains magic number geodesic subdivision level and Record magnitude range Zone Records A list of how many records there are for each zone The length of the zones section depends on the level value from the header Star Data This section of the file contains fixed size star records as Records described below Records do not contain zone information which must be inferred by counting how many records have been read so far and switching zones when enough have been read to fill the number of stars for the zone as specified in the zones section above The value of n used in the offset description is the number of zones as described above Table D 4 File sections D 2 3 Record Types D 2 3 1 File Header Record The Fil
128. t support depends on your binary Ogg Vorbis format is recommended WAV format should work but is discouraged because in this case the audio track will not adjust if the script is fast forwarded This is a current limitation of the SDL Mixer library emm o E state natural Turn off fog and all labels lines and art Turn planet star and nebula rendering on Deselect any selected ob jects Return to initial fov and viewing direction If state is natural ground and atmosphere will be turned on oth erwise these will be turned off date local i Set time to a specified date and or time using current timezone T is literal utc IYYYY MM DDThh mm ss Set time to a specified date and time in UTC time T is literal deselect Deselects current object selection including any constel lation selection See select command 51 APPENDIX B SCRIPTING COMMANDS Command Argument Names Argument Values Notes atmosphere azimuthal_grid on off 0 toggle Set rendering flags One argument name per com bright_nebulae mand allowed currently track object is only useful cardinal_points while an object is selected The following flags are key chart user settings and are not accessible from scripts en constellation_art able_move_keys enable_move_mouse enable_tui_menu constellation boundaries enable zoom keys gravity labels help horizon infos constellation dr
129. the telescope server is run ning The TCP port number which the telescope server is listening to delay This determines how Stellarium displays the current location of the telescope This is a numeric value expressed in microsec onds e g 500000 half a second ago Table 5 13 Telescope server parameters 2 Set up a telescope and start a telescope server for it see section 5 13 1 3 Add a new section telescopes to the main configuration file One line per telescope is required Each line starts with the numerical ID of the telescope and a colon separated list of connection parameters name protocol hostname port number and delay See table 5 T3 for an explanation of these terms For example these settings define two telescopes named irst 1x200 and second 1x200 These telescopes are controlled by two separate instances of the LX200 telescope server running on the local machine on TCP ports 10000 and 10001 respectively astro flag telescopes true flag telescope name true telescopes 1 first 1x200 TCP localhost 10000 500000 2 second 1x200 TCP 10calhost 10001 500000 5 13 3 Keyboard Controls To make a telescope point at the currently selected object in Stellarium simply press CTRL telescope number e g for the telescope first 1x200 configured in the ex ample in section 5 13 2 press CTRL 1 5 14 Image Flipping When viewing through a telescope the image one sees is often mirrored To aide use wit
130. this License However parties who have received copies or rights from you under this License will not have their licenses terminated so long as such parties remain in full compliance 10 FUTURE REVISIONS OF THIS LICENSE The Free Software Foundation may publish new revised versions of the GNU Free Documentation License from time to time Such new versions will be similar in spirit to the present version but may differ in detail to address new problems or concerns See http www gnu org copyleft Each version of the License is given a distinguishing version number If the Document specifies that a particular numbered version of this License or any later version applies to it you have the option of following the terms and conditions either of that specified version or of any later version that has been published not as a draft by the Free Software Foundation If the Document does not specify a version number of this License you may choose any version ever published not as a draft by the Free Software Foundation 95 Appendix K Acknowledgements Primary author Sky guide exercise ideas Celestial sphere diagrams nu merous corrections Mac platform specifics Windows platform specifics Large parts of Appendix G Customisation of fab files Makeing a custom landscape Appendix E Japanese translation many cor rections Colour magnitude diagram The rest of the Stellarium devel oper team Matthew Gates matthew
131. to effect immediatley Sky Culture The sky culture is the astronomical tradition used to define the constellations and common star names This setting also affects constellation art which at time of writing is only available for the Western sky culture Changes to this setting come into effect immediatley Save as default button This buttons saves yor language settings so that future Stellarium sessions use the settings If you do not save your changes will be lost when Stellaium exits 24 Chapter 5 Advanced Use 5 1 Files and Directories Stellarium has many data files containing such things as star catalogue data nebula images button icons font files and configuration files In version 0 9 0 of Stellarium there has been a re organisation of these files in an attempt to make it easier for third parties to make and distribute their own add ons for Stellarium such as landscapes scripts nebula textures and so on When Stellarium looks for a file it looks in two places First it looks in the user direc tory for the account which is running Stellarium If the file is not found there Stellarium looks in the installation director Thus it is possible for Stellarium to be installed as an administrative user and yet have a writable configuration file for non administrative users Another benefit of this method is on multi user systems Stellarium can be installed by the administrator and different users can maintain their own configurat
132. torial Grid Draws grid lines for the RA Dec coordinate system Toggles drawing of the ground Turn this off Toggle Ground to see objects that are below the horizon Toggle Cardinal Points Toggles marking of the North South East and West points on the horizon Toggle Atmosphere Toggles atmospheric effects Most notably makes the stars visible in the daytime Nebulae amp Galaxies Toggles marking the positions of Nebulae and Galaxies when the FOV is too wide to see them Coordinate System Enter Toggles between Alt Azi amp RA Dec coordi nate systems Centres the view on the selected object Flips the image in the horizontal plane Note Space CTRL SHIFT h this button is not enable by default See sec Flip image vertical CTRL SHIFT v Flips the image in the vertical plane Note this button is not enable by default See section 5 14 Q Search CTRL f Toggle the display of the object search win dow Configuration A 1 digit one Toggle the display of the configuration win dow Night Mode none Toggle night mode which changes the col oring of same display elements to be easier on the dark adapted eye Table 3 6 Main tool bar buttons 12 3 1 TOUR CHAPTER 3 INTERFACE GUIDE 3 1 4 The Object Search Window Object Search Search for eg Saturn Polaris HP6218 Orion M31 Q GO Autocompletion is TODO Figure 3 3 The search window The Object Search win
133. uration window allows for adjustment of the way Stellarium draws the scene All the controls are check boxes or numerical spin buttons By choosing values and then clicking the button labelled Set as default the user can select what options will be set when the program is started in future Table shows a list of these options and describes what they do Configuration Stars Star Names Up to mag Star Twinkle Amount Nebula Names Up to mag Also display Nebulas without textures Plan Moon Scale Planet Hin Equatorial Grid Equator Line Azimuth Ecliptic Line Cardinal Points Atmosphere Fog Meteor zenith hourly rate Normal rate 80 110000 0 144000 Save as default Figure 4 5 Configuration window rendering tab 4 6 Language Settings Stellarium supports several languages to some degree although the internationalisation process is not yet complete When you first start Stellarium it will try to determine the most appropriate language settings from your system settings You may also customise your language settings in the Language tab of the configuration window see figure 4 6 In the language tab there are the following controls Program Language This is the language which is used for the user interface of the pro gram i e text in windows mouse over hints for the button bars etc If you change More precisely with Stellarium is built using the QT library th screen resolution list is not populated QT is
134. vailable in the landscape ini file viewing atmosphere fade duration float sets the time it takes for the atmosphere to NN Pom viewing flag constellation drawing bool set to true if you want to see the constellation viewing flag constellation name bool set to true if you want to see the constellation 47 APPENDIX A CONFIGURATION FILE viewing flag_constellation_art bool set to true if you want to see the constellation pc BN viewing flag constellation boundarids bool set to true if you want to see the constellation viewing flag constellation isolate selebteol when set to true constallation lines bound aries and art will be limited to the constella tion of the selected star if that star is on one of the constellation lines viewing flag constellation pick bool set to true if you only want to see the line drawing art and name of the selected con stellation star viewing flag azimutal grid bool set to true if you want to see the azimuthal p JE ql iewi fl viewing flag equator line bool set to true if you want to see the equator line on start up viewing ag equatorial grid bool set to true if you want to see the equatorial grid on start up viewing flag ecliptic line bool set to true if you want to see the ecliptic line on start up viewing flag meridian line bool set to true if you want to see the meridian viewing flag_cardinal_points bool set to false if you don t want to see the car M
135. ve the file name extension sts Some scripts may use image files These may be placed in the same directory as the sts file unless aome other path is specified in the script when referring to such files 5 51 Running Scripts 1 Press the n key to open the text menu Use the cursor keys to select option 7 1 local scripts Press return and the select and exit to run text will be highlighted 2 Use the up and down cursor keys to select your script Press return and then exit the text menu with the m key and the script will start to execute Note that while scripts are running some key bindings are altered Specifically the time rate keys j k and 1 alter the rate at which the script progresses and may press CTRL c to stop the script and result normal operation If you created a new script file while the text menu was active you must turn off the text menu and turn it on again before the script will be avaiable in the menu 5 5 2 Recording Scripts Pressing CTRL r will start and stop script recording Refer to section 5 find out where script files will be created for your operating system Recorded script files are created with a file name recorded sts where the is a three digit number Thus the first recorded script will be called recorded 000 sts the second recorded 001 sts and so on The Stellarium wiki has a page containing a list of user contributed scripts 29 5 6 VISUAL EFFECTS CHAPTER 5 ADVANCED USE If
136. ver the nearby lamp seems much brighter it has a much greater apparent magnitude When astronomers talk about magnitude without specifying whether they mean apparent or absolute magnitude they are usually referring to apparent magni tude The magnitude scale has its roots in antiquity The Greek astronomer Hipparchus de fined the brightest stars in the sky to be first magnitude and the dimmest visible to the naked eye to be sixth magnitude In the 19th century British astronomer Norman Pogson quantified the scale more precisely defining it as a logarithmic scale where a magnitude 1 object is 100 times as bright as a magnitude 6 object a difference of five magnitudes The zero point of the modern scale was originally defined as the brightness of the star Vega however this was re defined more formally in 1982 2 Objects brighter than Vega given negative magnitudes The absolute magnitude of a star is defined as the magnitude a star would appear if it were 10 parsecs from the observer Table E2 lists several objects that may be seen in the sky their apparent magnitude and their absolute magnitude where applicable only stars have an absolute magnitude value The planets and the Moon don t give out light like a star does they reflect the light from the Sun 3 5 Luminosity Luminosity is an expression of the total energy radiated by a star It may be measured in watts however astronomers tend to use another expression solar lu
137. you wish to rename a recorded script you should simply navigate to the scripts sub directory of the user directory and rename the file as appropriate see section 5 1 for the location of the user directory on your operating system 5 5 3 Editing Scripts Manually editing a script file may be done using a simple text editor To get yourself started record a quick script go to a few objects using find and clicking on them zoom in and out using auto zoom and see what this generates in the script file For a complete list of scripting commands see appendix B 5 5 4 Example script This example script shows the occultation of Jupiter by the Moon in 2004 Note that the atmosphere and ground rendering is turned off so that they are not in the way if the location of the observer is set such that the event is not in the night time and or above the horizon This is a useful technique for scripting to avoid the need to set the location clear flag atmosphere off flag ground off wait duration 2 date local 2004 12 778 39 32 select planet Jupiter pointer off flag track object on zoom fov 0 5 wait duration 2 timerate rate 30 Script action end 5 5 5 Scripting Hints and Tips e When writing scripts it s useful to use the script bar to try out individual scripting commands see section e Explicitly set all the display options at the start of each script you can t guarantee what state the user s application will have e Explicitly
138. zon split into a number of smaller side textures and a separate ground texture This has the advantage over the single image method that the detail level of the horizon can be increased further without ending up with a single very large image file The ground texture can be a lower resolution than the parorama images Memory usage may be more efficient because there are no unused texture parts like the corners of the texture file in the fish eye method On the negative side it is more difficult to create this type of landscape merging the ground texture with the side textures can prove tricky The contents of the landscape ini file for this landscape type is also somewhat more complicated than for other landscape types Here is the landscape ini file which describes the Guereins landscape landscape name Guereins type old style nbsidetex 8 tex0 guereins4 png texl guereins5 png tex2 guereins6 png tex3 guereins7 png tex4 guereins8 png tex5 guereinsl png tex6 guereins2 png tex7 guereins3 png nbside 8 side0 tex0 0 0 005 1 1 sidel tex1 0 0 005 1 1 side2 tex2 0 0 005 1 1 side3 tex3 0 0 005 1 1 side4 tex4 0 0 005 1 1 Side5 tex5 0 0 005 1 1 32 5 7 CUSTOMISING LANDSCAPES CHAPTER 5 ADVANCED USE Figure 5 1 Multiple Image Method of making landscapes side6 tex6 0 0 005 1 1 side7 tex7 0 0 005 1 1 groundtex guereinsb png ground groundtex 0 0 1 1 fogtex fog png fog

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