User`s guide (Acrobat pdf format)
Contents
1. Ve SCE COUN IRS ces ca RE INUBESESEEU assen dooa e aS S See Fede IRE INE deca En OE nde eee Vel The Options Dialog inse 2 eter t e tete ee eet A cue OR ARR OTRA ERE Hes dein eds 8 Vad A Accessand PassWord pertoni OR t ee EET RU RE RENE UR EEREVON M A E OE DG RR RETE 8 V 1 2 The Save Options File PHOTOPTS INI eese enne nennen ne etrenneeneee tre tenen netten erret ene 8 V 1 3 File Path and File Names 5t ted tee ete er Rr pbi e pir dad AEE 9 V 1 4 Parameters and Selectable Options sees enne eren etre nennen nenne nenne teeenne ee 9 V22 Bitmap BMD Files uen pan deett epp eee E ER ERE treat bo Peer ho ete RE 10 Vz3 Help CHEP Files iier UE Sega RE pierre 10 V 4 Data DAT Piles wi 5 irrien oiie hte o PE o ae EE Ue S Ete bete CDU ER 11 V4 1 Star Fields List File ne RR up Ae n ew hi acad iu EH 11 V 4 2 Stellar Data Piles nesciens eee RR HR TREE IER rai eee reser 12 V 4 3 Field Coordinates and Angular Size sesssssesssseseseseeeeeene ener enne en entren nenne etre trennen trennen 13 V 5 Logout Reminder File iau ener REO SER Fr E ubansas hep E e D ERE R EEEE EES 13 VI Astronomical Data Models and Algorithms eee e ecce ee ee ee eee eene eee eese esse eeesssseesss LD MISI Star Images aedes eg epe e tas ess Ron ena Ret peu eat ue eae a I Ras 13 VI 2 Pleiades Photometric Datta icsecdcecssseccesedscessoce costa edhe cc cen ssveu2. 16 colors in our development of these programs but many of the available image files do not display well in 16 colors and so we have adopted 256 colors as our standard Individual discussions of color resolution and changing video drivers are presented in Sections II 4 1 through II 4 3 PAGE 3 Technical Manual II 4 1 Color As noted best results will be obtained with this exercise when Windows is configured with a graphics driver that uses 256 colors These exercises are not designed for monochrome monitors and are not generally usable in monochrome If you are running Windows with a 16 color video card and or driver the software will detect this and access special 16 color bitmaps where required These are satisfactory but not as eye catching as the 256 color versions In this exer cise only the logo and title screens have a noticeably different appearance on a 16 color display The star images Section VI 1 change slightly since only a few levels of gray scale are available If your video card supports 256 colors you may be able to change the Windows driver to one that makes use of the full color range see Section II 4 3 The exercise software will then automatically use the 256 color versions of the bitmaps II 4 2 Resolution Size This exercise is designed to display full screen in a 640x480 pixel graphics mode Higher resolution modes 800x600 1024x768 may also be used the display will appear smaller but properly
3. then appears as the default on the login dialog The table number has a maximum length of 4 characters but need not be numeric V 2 Bitmap BMP Files Files that contain graphics images for display by this software must be in Windows bitmap BMP format Many available software packages that edit or create graphics images offer BMP file output as an option and many will convert other formats GIF PCX etc to BMP You will find that BMP files are usually larger than other formats often much larger Windows has apparently taken the route of trading memory disk space for display speed Due to the color issues discussed in Section Il 4 we provide 256 color and 16 color versions of almost all bitmaps Again many available graphics editing programs will reduce the number of colors to the standard 16 of VGA and often offer a number of different techniques to accomplish this We have found that methods which blend or dither the colors usually produce more satisfactory results than methods which simply map to the nearest color Users who wish to do so may provide their own logo and or title screen s to replace the one s furnished You will need to develop a 652x436 pixel image in BMP format Depending on the type of equipment you are using you will need to create 256 color and or 16 color versions You can then enter the file names in the appropriate fields on the options dialog or you can give your files the same names as the o
4. a minimum of 2 MBytes of RAM For optimum performance we recommend a fairly fast processor capable of running Windows 386 Extended mode 25 MHz 386SX or above with 4 MBytes or more of RAM A floating point coprocessor Intel 80x87 or equiva lent is highly recommended but is not required A Weitek coprocessor should cause no problems if present but is not used A mouse is a definite requirement but you need not load a separate mouse driver if you use a mouse with Win dows A color display VGA or better is required a high speed high resolution video card driver is advantageous see Section II 4 II 2 Operating System This software runs under Microsoft Windows Versions 3 0 and 3 1 and compatible modes on later versions and or equivalents You cannot run it standalone under DOS II 3 Disk Space A hard disk is required This exercise uses approximately 1 1 MByte of disk space You can reduce this somewhat by deleting unneeded bitmap files see Section V 2 II 4 Video Issues Unfortunately beyond VGA 640x480 16 colors and SuperVGA 800x600 16 colors there is very little standardiza tion in video cards drivers used to run Windows Most newer cards offer additional modes resolutions to 1024x768 and beyond and 256 and more 16K colors and many Windows users are probably unaware of how their system is configured and what mode they are using We have attempted to address the lowest common denominator VGA 640x480 pixels
5. be present in your working directory after unpacking the distribution ZIP file Section III 1 README PHO Notes on the current version including any incompatibilities with previous versions old files that should be deleted etc UPDATE PHO A list of updates by version since version 0 50 USRGUIDE PHO This document in text form CLEA PHO EXE The executable code for the exercise CLEALOGO BMP 256 color bitmap data for the CLEA Logo screen CLEALG16 BMP 16 color bitmap data for the CLEA Logo screen PLEIALAB BMP 256 color bitmap data for the Title screen PLEIAL16 BMP A 16 color version of the Title screen PHOFILES DAT A list of files containing star fields and the field coordinates see Section V 4 1 PLEIADES DAT Positional and photometric data for the Pleiades stars see Section V 4 2 CLEAHELP HLP Text for Help On Help PHOSTART HLP Text for Help Getting Started PHODATA HLP Text for Help Taking Data REMINDER PHO Text to display when Quit selected see Section V 5 PHOTOPTS IND This file is not included in the distribution but is created the first the exercise is run It contains default settings for options see Section V 1 2 This file can be deleted if desired it will then be re created V User Options CLEA exercises are ready to run as is in essentially the form that we have used with students in our introductory Astronomy classes However i
6. begin this process Then change to the directory C WINDOWS and type SETUP at the prompt III Installation and Operation III 1 Unpacking the Files All files for this exercise are compacted into the distribution file CLEA PHO ZIP They must be extracted using the PKUNZIP program also included on the distribution diskette and placed together in a single directory such as CAPHO LAB This exercise may be placed in the same directory as other CLEA exercises as the names of exercise specific files are unique to each This will result in a small savings in disk space since duplicate copies of the files CLEALOGO BMP CLEALG16 BMP and CLEAHELPHLP will not be needed We recommend however that you place each exercise in its own directory as there is then no confusion as to which files are involved when you wish to update or copy specific exercises It is possible to separate the executable code for the exercise from its image and data files This allows for example multiple set ups or variations of the same exercise See the discussion of the Path parameter in Section V 1 3 The unpacking process is probably best accomplished under DOS as follows E Access the DOS prompt If you are running under Windows you can either exit select File Exit Windows on the Program Manager menu or select the MS DOS Prompt icon from the Main probably program group 2 If you are not placing the exercise in an existing directory create a new
7. bias parameter that can be set by the user Section V 1 4 This number is used as the actual magnitude which corresponds to the magnitude 0 image When stars are plotted their magnitude is rounded to a whole number and the corresponding image is assigned Stars fainter than the adjusted end of the image range are all plotted using the faintest image Users who add new star fields to this exercise may want to experiment with various values of the bias parameter to yield a realistic and pleasing display We have found that the brightest images are perhaps a bit too bright and have set the bias parameter at 1 rather than 3 which is the magnitude of the brightest star in the Pleiades Do not set the bias parameter to a value that is larger numerically than the magnitude of the brightest star you are plotting We have not attempted to add color to the star images The images are displayed on the screen by setting all three color values RGB to the same level Intensities in the image data that exceed 256 in the original Mag 0 image the values go as high as 17 000 are set to 256 the highest available This yields a burned out center which is realistic for TV monitors When the images are displayed in a 16 color video mode Section II 4 the edges of the brighter images show some step contouring due to the limited number of grayscale values available VI 2 Pleiades Photometric Data The photometric data for the Pleiades supplied with this exe
8. directory For example C gt MD C PHO_LAB lt Enter gt 3 Go to the directory where you are placing the exercise For example C gt CD C PHO_LAB lt Enter gt 4 Place the CLEA distribution diskette in the proper disk drive for a high density 1 44 MB 3 1 2 inch diskette probably A or B 5 Assuming you have placed the disk in drive B enter the following for drive A substitute A for B C gt B PKUNZIP B CLEA_PHO lt Enter gt If you are replacing an earlier version in the same directory enter instead C gt B PKUNZIP O B CLEA_PHO lt Enter gt In this case replacement you should also check the README file that came with the updated software There may be special instructions such as additional files to delete In general any existing files in the directory with extension INI should be deleted If you have changed any options from their default values you will have to reset them when you run the new software see Section V 1 6 If you are placing the lab in the same directory as other CLEA labs you may get messages such as PKUNZIP Warning file CLEALOGO BMP already exists Overwrite y n In general you should respond y Yes to these messages but again check the README file PAGE 5 Technical Manual NOTE We highly recommend that you follow the above procedure unpack the ZIP file whenever you load this software on another machine Do not copy the unpacked files from one machine to anoth
9. help file simply create a text file we recommend a maximum of 72 characters per line copy it to the working directory and enter its name in the User Help File field on the options dialog You can also use a text editor to modify the existing help screens or create replacements V 4 Data DAT Files Data for the star fields and individual stars used in this exercise is read from files typically identified by the qualifier DAT These files like the HLP files Section V 3 are in text format and can be created and maintained with a text editor See remarks in Section V 3 concerning the use of word processors The specific record formats for the star fields list file and the stellar data files are given in Sections V 4 1 and V 4 2 respectively The following general rules apply Data should be entered one record per line 2 Fields within records are separated by at least one space Do not use commas or other separators and do not embed spaces in numeric fields 3 String fields are enclosed in single quotes and the number of characters spaces between the quotes must be lt the maximum length of the field 4 Real fields may carry a sign and may be in decimal 1 0 2 345 or exponential 0 1234E 06 8 549E 18 form Real fields will also accept integer 0 1 99 values 5 Integer fields may carry a sign and cannot include a decimal point or exponent 6 The maximum allowed values for all numeric fields in ter
10. itis used or when itis changed If the password change is verified you must also respond Yes to Save New Values in PHOTOPTS INI to have the change take effect The password is stored in a masked form in PHOTOPTS INI If you forget the password delete or rename PHOTOPTS INI and the password will again be CLEA In this case all options will return to their original internal default values V 1 2 The Save Options File PHOTOPTS INI The options settings for this exercise are stored in the file PHOTOPTS INI This file is created and placed in the working directory the first time this exercise is run regardless of whether or not the options have been modified If they have not the file will contain the internal defaults If you access the options dialog select Ok and respond Yes to Save New Values in PHOTOPTS INI a new copy of PHOTOPTS INI will be created and the old version will be renamed PHOTOPTS BAK If there is an existing PHOTOPTS BAK it will be lost PHOTOPTS INI is stored in binary not text format Changes should be made only via the options dialog not with a text editor If you are setting up the exercises on a number of computers in a laboratory you can set up one via the options dialog copy the resulting PHOTOPTS INI onto a floppy disk and load it into the appropriate directory on each machine Do not use a copy of PHOTOPTS INI with a different version of the exercise software than the one
11. which created it In most cases this will be caught by the software and you will be given the option of deleting PHOTOPTS INI or quitting the program If you are updating an exercise in place on top of an earlier version in the same directory you should delete any PHOTOPTS INI and PHOTOPTS BAK files in the directory before running the new version Pace 8 Version 1 0 Remember that you may need either to reset some options or copy in a correct version of PHOTOPTS INI after you do this V 1 3 File Path and File Names File names and a directory path may be entered in the identified fields on the options dialog File names should follow the normal DOS format a maximum of eight alphanumeric characters first character must be alphabetic optionally followed by a period and up to three characters as a qualifier Bitmap files are given the qualifier BMP help files carry the HLP qualifier while data files and file lists are identified by DAT Note that there are usually 256 color and 16 color versions of each bitmap file see Section II 4 for discussion Details of each type of file are given in Sections V 2 through V 5 The Directory Path field is provided so that a particular exercise can be used with an alternate set of files Under normal circumstances this field should be left blank and all the files related to the exercise should be placed in the directory identified as the Working Directory when the exercise is installed under W
12. Photoelectric Photometry of the Pleiades Software Users Guide A Manual to Accompany Software for the Introductory Astronomy Lab Exercise Document SUG 2 Version 1 Department of Physics Gettysburg College Gettysburg PA 17325 Telephone 717 337 6028 email clea gettysburg edu Contemporary Laboratory Experiences in Astronomy Contents I Introduction me ID IDEE EE 3 L2 Acknowledgments pepe too epe tee qom noted epe t e e ce ee 3 II System Requirements eee DE M1 Hardware n n e R np penne Ihe nennt iS 3 WE Operating Systetni EEA EE E EE ee EAEE E EE re EE 3 1 3 DIR Space itane perte oa eoa eu tud e eta e eet arn da S 3 M4s Vide ISS HES E PEE 3 IFAI Collota aer epp edet etr Pep ee ee ip e a ta tecti prede te n PR 4 JEEP Resolution SIZE veces crs deovechies Sescs deb 4 1I 4 3 Changing the Video Driver ere eee rtr sacepcebuccsvesnay EE VIE A OENE ESSEE Eain TEE EEES 4 IH Installation and Operation yes caet ne EARRE RAE PIER ICH NUR RR NEN NE SANUS ate IIIT 3 Unpackang the Files nre o Pet ER tete ie ente o PO ate on ea e en eR 5 III 2 Running the Exercise ote ra eR D ERE RE ERE p HP ERE tH e RE 6 II2 T File Manager arredo Rp IE D iU Ue dudes oo D De gies 6 III 2 2 Installation Under Windows oa hee mettere EEEE SEEE EEE ESS 6 IV Files Included With Exercise eee eee eee eese sese se sese sese sese sese sese sese sese se seseseseseseseseseseseses 7
13. cs cous eveueteees even Epe EN ESPEN PESES a NENE evens cy pae e een 14 VI 3 Observational Calculations 1r netter eere rre eer Pre Ves reserves eere ee esee pa vaa eere ee ves epa RE 14 RREPEKENCES DA XM LO Version 1 0 I Introduction I 1 Purpose This document provides information for users of the CLEA software module Photoelectric Photometry of the Pleiades It includes discussions of hardware and operating system requirements Section II software installation and operation Section III files associated with the exercise Section IV user options and file formats for possible user modifications Section V and astronomical data models and algorithms employed in the exercise Section VI The material in this guide is intended for use by the instructor and by other personnel involved in installing and configuring the exercise software and PC hardware It is not intended for distribution to the students The word user as it appears in herein should be interpreted as instructor and not student I 2 Acknowledgments Development of CLEA exercises and materials including this guide is supported in part by National Science Foundation Grant USE 9155927 and by Gettysburg College II System Requirements II 1 Hardware This exercise should run successfully on any IBM or compatible PC capable of running Microsoft Windows 3 0 or 3 1 This includes processors Intel 80286 or equivalent and above 80386 80486 Pentium with
14. de B V Color U B Color Comment Note 1 Notes Data Type String 15 Real Real Real Real Real String 23 Contents Optional Note 2 star name HD BD number id in cluster or other identification RA of star in decimal hours 0 0 24 0 Dec of star in decimal degrees 90 0 90 0 Photoelectric magnitude in UBV system Photoelectric color index in UBV system Photoelectric color index in UBV system Optional Note 2 additional information spectral type binary etc 1 If the Show ID Comments switch Section V 1 4 is set the contents of this field will appear on the screen when the star is measured 2 Enter two single quotes to blank out this field Pace 12 Version 1 0 V 4 3 Field Coordinates and Angular Size When creating new star fields for this exercise or modifying existing fields give consideration to the following 1 The finder wide field of the simulated telescope is 2 5 degrees square Users may want to provide a larger field to avoid having part of the visible field go blank when slewing to stars of interest 2 The object of interest probably a cluster should be centered in the field The coordinates of the field center should be entered in the star field list file Section V 4 1 3 Avoid high declinations stay within 60 dec 60 The display algorithm is relatively simple similar to a Mercator projection 4 Similarly avoid fields that straddle the 24H
15. epends on the video mode and employs variable length characters so the resulting line length is nearly impossible to predict It is recommended that CRLF be used only to terminate paragraphs which then become long lines subject to the length restriction above Some experimentation may be required to achieve a message that displays as intended We have provided a default reminder file REMINDER PHO which may be used as is modified with a text editor replaced or simply deleted if desired If no reminder file is provided to the program a short message Do You Really Want to Quit This Exercise is displayed when Quit is selected VI Astronomical Data Models and Algorithms VI 1 Star Images A frequent problem with much astronomical software we have seen even some that is otherwise quite sophisticated is that the plotted star fields do not look realistic The most common techniques are to either plot all stars as a single pixel of the same intensity or to use filled circles of varying sizes to represent the magnitudes Pace 13 Technical Manual The problem with the first method is that while the images look somewhat like stars the field does not look like the sky picking out constellations or other patterns is difficult and attempting to vary the intensity of a single pixel yields a useful range of only two or three magnitudes On the other hand the second method yields images that look nothing at all like stars
16. er This is particularly true if you have made any configuration changes Section V and especially if you have deleted any files Our software has some internal ability to adapt to its surroundings but it must all be present in its original form to accomplish this For this reason we ask that if you distribute this software to others you distribute only the original ZIP version III 2 Running the Exercise As noted in Section II 2 this exercise must be run under Microsoft Windows Versions 3 1 or 3 0 Once you have installed the software and have started or returned to Windows you may run the exercise from the Windows File Manager or install it under Windows and run it from an icon III 2 1 File Manager As a quick method of running the exercise access the File Manager by double clicking on its icon probably in the Main program group window Access the directory where the you have loaded the files and double click on the entry for CLEA PHO EXE Alternatively select File Run from either the File Manager or Program Manager menu and enter the appropriate command line for example C PHO_LAB CLEA_PHO EXE III 2 2 Installation Under Windows As part of a permanent installation and certainly for student use the exercise should be installed under Windows The procedure for this is as follows assuming the software has been unzipped into directory CAPHO LAB 1 If you have already created a program group to hold CLEA exercise
17. indows Section III 2 2 If a path following DOS conventions is entered in this field it should point to a directory that contains a complete set of bitmap data and help files for the exercise with all files correctly named in the appropriate options dialog fields or in the star fields list file PHOFILES DAT Section V 4 1 V 1 4 Parameters and Selectable Options The following switches on the options dialog enable features that simplify the exercise by providing information not normally available at the telescope Show Magnitude When this switch is on the measured magnitude is computed and displayed on the screen when a reading is taken If this switch is off the student must compute the magnitude from the raw counts and measure ments of standard stars The default is ON Show ID Comments W hen this switch is on the contents of the ID and comments fields from the star data record see Section V 4 2 are displayed on the screen when the star is measured This can be used to determine whether the correct stars are being measured and to provide information such as spectral type binary nature etc to the students The default is OFF Show Field Size When this switch is on the size of the field in the viewscreen is displayed If this switch is off the students can determine the field size by turning off the drive and timing the diurnal drift through the field The default is ON NOTE The size of the Finder field is curren
18. ld ones and replace them in the working directory If you will always run in the same color mode 256 color or 16 color you can free some disk space by deleting the unused BMP files Use the list in Section IV to determine which BMP files are for the mode you are not using and can therefore be deleted The 16 color BMP files usually have 16 somewhere in their name If you choose to delete files be aware that you will need these files if for any reason you change the color mode or copy the software to a machine that runs in a different color mode also see NOTE Section III 1 V 3 Help HLP Files Help files qualifier HLP for the CLEA Windows exercises are simply text files which can be created and modified with a text editor including the MS DOS editor provided with Versions 5 0 and above access MS DOS and type EDIT Text files can also be created with a word processor If you use a word processor be sure that you generate your final output in straight ASCII text not in the word processor s internal format or formatted for a printer Most word processors have an option to generate ASCII text Pace 10 Version 1 0 You may also need to eliminate page breaks It may be cumbersome or difficult to edit existing text files with some word processors We have provided the User Help menu item to accommodate specific instructions information etc that the instructor may wish to impart to the students To create a user
19. ms of both absolute value and number of digits are much larger than required for any reasonable values for the quantities they represent 7 Values must be provided for all fields in a record in the proper order For null strings enter two single quotes for null numeric fields enter 0 or 0 0 8 There is no specific limit on the number of records in a file However these files are read into and maintained in memory when they are used so there is some risk of running out of heap space with a large file To add a new star field to the exercise you must create a stellar data file Section V 4 2 place it in the exercise directory Section III and add a record to PHOFILES DAT Section V 4 1 naming the file and specifying its coordinates Before creating new fields or adding data to existing fields you should read Section V 4 3 which presents some restrictions and guidelines on star field coordinates and sizes V 4 1 Star Fields List File This file provides a list of the files that contain the stellar data for each star field along with the coordinates of the field centers It is identified in the field labeled Star Field List on the options dialog Section V 1 the default is PHOFILES DAT Pace 11 Technical Manual Records in this file have the following format see general rules under V 4 Field File Name Right Ascension Declination Data Type String 12 Real Real Contents Name of stellar data file name
20. n order to make the exercises as flexible as possible we have included a number of options that allow the user to tailor the exercise to specific course requirements and level of difficulty In this exercise the instructor can modify the photometric data for the Pleiades stars add additional stars add additional clusters or star fields and modify add help screens Further options provide some selection of the amount of information to be furnished to the students as well as magnitude scaling of the star images PAGE 7 Technical Manual This adaptability is achieved through two mechanisms an options dialog that enables the user to select built in options and change file names and path and the files themselves which in many cases can be modified or replaced The options dialog for this exercise is presented in Section V 1 while modifications to the various file types are discussed in Sections V 2 through V 5 V 1 The Options Dialog CLEA exercises feature an options dialog that allows the user to select built in options change file names and provide a path for the bitmap and data files A password is required for entry into this dialog to prevent access by the students V 1 1 Access and Password Access to the options dialog is provided through the Log In Student Accounting screen Select Log In from the main menu and type Instructor no quotes not case sensitive in the field labeled Student 41 No other entry on the fo
21. ollowing is a general outline of the basic steps required to change the video driver in Windows 3 1 The procedure for Windows 3 0 is similar but some differences may be encountered 1 Have the following on hand your Windows installation disks any disks containing drivers and other software that came with your video card 2 Start Windows From the Main window select Windows Setup 3 Select Options then select Change System Settings 4 Select Display A list of drivers will appear with your current driver highlighted You should make a note of it so you can return to it later If a driver appropriate to your video card and desired mode appears on the list select it If you are installing a driver that came with your card and it does not appear on the list select Other 5 Follow the directions that appear You may want to perform the process several times to sample various modes Once specific drivers have been loaded you can switch between them fairly rapidly using the above procedure you do not need the Windows and drivers disks PAGE 4 Version 1 0 Caution This procedure is not without its hazards For example if you select and install a driver mode that is not supported by your video card you may render Windows unusable In this case you will need to run SETUP from DOS to restore your original driver If you start Windows from your AUTOEXEC BAT file you will probably have to boot DOS from drive A to
22. proportioned This can be advantageous as Help and sometimes Result windows can be brought up re sized if necessary and re positioned on the screen so that they can be referred to directly as the exercise proceeds The process for changing the resolution is the same as that for changing the color mode you must change the video driver following the steps outlined in Section II 4 3 One minor complication is that the fonts do not scale exactly between all graphics modes This sometimes results in oversized labels on the control buttons and truncated text lines with a horizontal scroll bar on the Help windows If this occurs on your Help window simply drag the right side of the Help window outward until the horizontal scroll bar disappears and the text lines will be visible in their entirety II 4 3 Changing the Video Driver If your computer is currently running Windows in a 16 color mode and you would like to improve the appearance of the displays and or you would like to try a different screen resolution you may be able to change the Windows video driver if your video card will support the mode you want Begin by consulting your Windows documentation and installation procedure for information on installing checking changing the graphics driver Also check the documentation and any software that came with your video card A Windows driver or drivers may have been included and the documentation may describe the installation procedure The f
23. qualifier no path RA of field center in decimal hours 0 0 24 0 but see Section V 4 3 Dec of field center in decimal degrees 90 0 90 0 but see Section V 4 3 When the telescope is moved via the Set Coordinates button the program searches the star fields list to find the field center closest to the target coordinates and loads the corresponding star data file NOTE the star fields list is not searched during a slew using the N S E W buttons Itis therefore possible to slew off a star field into empty space even though a neighboring field may be available Always use the Set Coordi nates button to change fields Of course if the nearest field center is too far away or the field is small you may still get an empty screen V 4 2 Stellar Data Files These files contain the data magnitude color etc for each star in a star field Each entry in the star fields list Section V 4 1 identifies a stellar data file which must be present in the working directory when the exercise is run Note that these files are not identified on the options dialog Section V 1 Only one of these files PLEIADES DAT is supplied with the exercise but the user may add as many as desired supplying corresponding entries in PHOFILES DAT and may also add delete modify data in PLEIADES DAT Stellar data file records have the following format see general rules under V 4 Field Star ID Note 1 Right Ascension Declination V Magnitu
24. r 0Hr dichotomy in right ascension The program will not identify a coordinate of for example 23Hr 50Min RA as being near one at OHr 5Min etc We have developed a separate program GENSTARS which can be used to generate random star fields primarily for backgrounds The GENSTARS program and documentation is included with the CLEA exercise The Hubble Redshift Distance Relation GENSTARS output requires some text editor modification including deletion of some record fields and the possible addition of color data for use with this exercise V 5 Logout Reminder File This optional file provides a mechanism for the instructor to supply customized messages to the students when they have finished the exercise The contents of the text file identified in the Reminder File field on the options dialog are displayed whenever Quit is selected from the main menu This display always concludes with the line Select OK to Quit Exercise Cancel to Continue and provides pushbuttons affording the appropriate choices A reminder file can be any text file create with a text editor with the following restrictions The total message may not exceed 1023 characters A line see next may not exceed 255 characters Carriage return line feed CRLF characters in the file will result in new lines in the output However additional new lines may appear because the output will wrap itself automatically This wrapping d
25. rcise in PLEIADES DAT is taken from Hendon and Kaitchuck 1990 with additional data from Blanco et al 1968 Some non cluster members are included VI 3 Observational Calculations The following Pascal functions compute the observed quantities NoisyCount and Magnitude We present this material in this format rather than as mathematical formulae so that this document can be distributed as ASCII text The underlying mathematics should be readily apparent In this code Mag the star s magnitude from the stellar data file Mag V V Mag B B V V Mag U U B Mag B Seconds Integration time of the observation MeanSky Measured mean sky count in the appropriate color The values used for CountBase and MagBase are more or less arbitrary Pace 14 Version 1 0 The code follows type FilterType U B V const SkyMag array Filter Type of Float 17 33 17 0 16 0 CountBase 10 MagBase 18 0 function BaseCount Mag Float Float var Exp Float begin Exp Mag MagBase 2 5 BaseCount CountBase raise 10 0 Exp end BaseCount function NoisyCount Mag Seconds Float Float var Count Float SNR Float LoLimit Float Range Float begin Count BaseCount Mag Seconds SNR sqrt Count LoLimit Count SNR Range 2 SNR NoisyCount LoLimit Random Range end NoisyCount function Magnitude Count LongInt Interval Float MeanSky Float Float var Base Floa
26. rm is required After entering the above select Ok and then Yes to Have You Finished Logging In A small dialog box will appear asking for the password Enter the password see next paragraph and select Ok If you have entered the correct password the dialog labeled Startup Parameters Options will then appear The tab key and shift tab may be used to move from field to field or you can select fields directly with the mouse When you are finished select Ok or Cancel If you select Ok the message Save New Values in PHOTOPTS INI will appear If you select Yes the options as they appear on the dialog screen will be saved and used as defaults the next time the exercise runs If you select No the options you have set selected will be used only for the current execution Once you have made your selection the exercise will begin NOTE Once you have passed the Log In screen you cannot access the options dialog To do so you must quit and rerun the exercise The default options password is CLEA in caps no quotes The default is in effect until it is changed and at any time that the software cannot locate the PHOTOPTS INI file in the working directory You may change the password from the options dialog 16 characters or less case sensitive If you do a small dialog box will appear asking you to repeat the new password for verification Note that the password is never echoed either when
27. s select it from the Program Manager window and go to step 4 If not proceed with step 2 2 From the Program Manager menu select File New Program Group Click on OK 3 Enter CLEA or other descriptive title in the Description field The Group File field may be left blank Click on OR 4 From the Program Manager menu select File New Program Item Click on OK 5 Enter the following in the identified fields Description Pleiades Photometry Command Line C PHO_LAB CLEA_PHO EXE Working Directory C PHO_LAB Shortcut Key None Run Minimized No 6 Click on OK The exercise may now be run by selecting the CLEA program group from the Program Manager window and double clicking on the CLEA icon labeled Pleiades Photometry PAGE 6 Version 1 0 IV Files Included With Exercise The software module for each CLEA exercise includes a largely unique set of files that are vital to its operation In addition to the executable code for the program EXE these files hold the bitmaps for the screen displays BMP data and parameters for the astronomical objects in the exercise DAT text for the Help screens HLP startup parameters CIND and documentation PHO Many of these files can be modified or replaced to tailor the exercise to specific classroom requirements see Section V The following files comprise this exercise and should
28. t begin Base Count Interval MeanSky Magnitude 2 5 log Base CountBase MagBase end Magnitude References Blanco V M Demers S Douglass G G and Fitzgerald M P Photoelectric Catalogue Publications of the United States Naval Observatory Second Series Vol XXI 1968 Hendon A A and Kaitchuck R H Astronomical Photometry Richmond Willman Bell 1990 Pace 15 Technical Manual Pace 16 Version 1 0 Pace 17 Technical Manual Pace 18 Version 1 0 Pace 19 Technical Manual Pace 20
29. tly fixed at 2 5 degrees see discussion in Section V 4 3 The Instrument field is one tenth the Finder field 0 25 deg 15 The following parameters are set via the options dialog UT Local Time Hrs The value in integer hours of Universal Time minus local zone time for the presumed location of the observatory for this exercise This number is used to convert the time obtained from the system clock on the individual PC to Universal Time The table below gives the standard time values for North American time zones For daylight time subtract one from the table value The default is 5 hours Eastern Standard Time PAGE 9 Technical Manual Zone UT ST Hrs Atlantic Eastern Central Mountain Pacific Alaska Hawaii OoN DARA Image Bias Mag The value integer of the magnitude bias to be used when mapping the magnitudes from the star data Section V 4 2 onto the available star images for display For details see Section VI 1 This parameter must be equal to or less than numerically the magnitude of the brightest star in the field rounded to a whole number The default is 1 Options Password This is the password for access to the options dialog see Section V 1 1 Allowable passwords have a maximum length of 16 characters and are case sensitive The default password is CLEA Table Number This field allows the instructor to preset the table number for each machine in the lab This number
30. with the brighter stars being large sharp edged circles some as large as dimes As we feel that it is important for the students to appreciate the true appearance of the sky both to the naked eye and through various astro nomical instruments we devoted some time to the creation of more realistic looking star images for this and for other CLEA exercises Clearly the ideal way to display a realistic star image is to use a real star image which will not be smooth and perfectly round but will have natural irregularities caused by seeing optics etc A CCD image is the obvious choice since it is already in digital form We began by selecting a single fairly bright CCD star image We then developed a series of successively fainter images by reducing the intensities pixel by pixel in equal stages The factor used to decrease the intensity at each stage was experimentally adjusted balancing the desire for a reasonably wide magnitude range against the need for each image to be clearly fainter in appearance than its successor The faint end of this process was reached when the resulting image was barely visible on the screen against a black background This eventually resulted in a series of 11 images The brightest image was more or less arbitrarily assigned magnitude 0 and each succeeding image increased by 1 magnitude to give a base magnitude range of 0 through 10 To provide for zero point adjustment for fainter clusters we added an image
Download Pdf Manuals
Related Search