Observer`s Guide for the Martin Observatory 14
Contents
1. 4 1 Slewing the Telescope to an Object If you wish to slew the telescope to a specific object chances are it s in TheSky s database and you can use the following steps to slew to it 1 Click on the Find button in TheSky or select Edit Find in the menu A dialog box will appear in which you can enter the name of the object or select it from one of the catalog lists Once you have selected your object an Object Information box will appear Alternatively simply clicking on an object in the virtual sky if you see it there will bring up its Object Information box 2 Check the altitude of the object shown in the Object Information box You should never slew to an object below the horizon altitude less than zero The telescope could be physically damaged if you tried and not simply because it might run into the pier the mount is not built to go that far You are the last line of protection for the telescope Please take care when setting up a slew 3 If the object is not below the horizon you can now slew the telescope to the object To do so click on the Slew button in the Object Information box it looks like a green telescope a Whatever you do never click on the Synch or Map but tons in the Object Information box those buttons are used only in an extensive setting up procedure for the telescope clicking on any of them would cripple the telescope s pointing ability negating many2. Click the Temperature button Make sure Temperature regulation is on and set the Temperature setpoint to the Recommended setpoint Shutdown regulation upon disconnect should be on checked 3 2 Normal Observing Normal observing consists of e Using TheSky to slew the telescope to an object and center the object in the field of view e Using CCDSoft to control the camera imaging with a selected filter focusing if necessary autoguiding if necessary for taking long exposures without tracking errors These steps might be repeated Some might be left out Sometimes the order is changed These choices are dependent upon your observing strategy dictated by the project you are attacking See the sections Using TheSky to Control the Telescope and Using CCDSoft to Control the Camera below for more information For lowest noise images highest quality you want the regulated temperature to be at the lowest possible value However you also want constant temperature the cooling capacity under Temperature at the bottom of the Panel should be less than 75 85 Note A very low setpoint might be recommended on especially cold evenings but don t set the CCD temperature lower than something like 25 C or 30 C This will avoid the formation of ice crystals on the inside surface of the CCD camera window which would produce rectangular shadows shapes or fingers in your images near the e
3. Light to take an image of the sky f Reduction is set to AutoDark to automatically take a Dark image after the Light image and then correct the Light image using this Dark before display g You then click on the Take Image or Take Series button 5 USING CCDSOFT TO CONTROL THE CAMERA 13 2 Use the Save or Save As menu item to save your image s to disk into the folder you creating during start up If you don t save the currently displayed image it will be replaced by the next image taken thus lost unless you have checked To new window under the Take Image tab Of course if you are set up for AutoSave your images are automatically named and saved as they are displayed Save your images in FITS format Flexible Image Transport System the astronomical standard Further camera control details are given in the subsections below Important Note any images acquired with our SBIG cameras have the value 100 added to each pixel before display or saving to a file Thus when you use the mouse cursor to check out the pixel values realize that each value has been increased by this bias value Any processing you do in CCDSoft or SBIG s software CCDOps compensates for this added 100 For example before these programs subtract one image from another both images have the 100 bias removed then the images are subtracted finally the difference image has a 100 bias added to it before it is displayed and it will be saved that way if
4. Use the Slit Controller s CLOSE button to close the slit if necessary Don t turn off the Slit Controller box If necessary return the Dome to it s park position orange markers aligned using the LEFT and RIGHT buttons for the Dome Con troller Turn off power to the Dome Controller Ground yourself then turn off power to the Paramount using the rocker switch on the South side of the equatorial head Unplug the Paramount s AC power adapter Unplug the power cord for the CCD camera power supply Unplug the white adapter for the camera s parallel to ethernet box Place the adapter on the pier s metal base plate Be careful no to put a twist in the adapter s cord as you place it on the telescope mount s base plate Gently put the telescope s lens cover in place There is no need to press it down hard Indeed if you do press it down that may make it difficult to remove next time without jarring the telescope a bad thing Gently disconnect connectors plugs A B C D and E Drape the serial connector E on the telescope pier don t leave it laying on the floor Turn off any lights in the dome as you exit the dome Lock the dome door using the key 8 Secure the control building a b c Copy all necessary image files from the computer to a flash drive Shut down the computer Start button Turn Off Computer wait until it turns off
5. be smeared out into streaks These can be eliminated by guiding on a star 5 USING CCDSOFT TO CONTROL THE CAMERA 16 keeping a star centered on a particular pixel in the small Autoguider CCD of the ST 8E while your object is imaged in the large Imager CCD chip CC DSoft can do this automatically In CCDSoftuse the following steps 1 Slew to the object you will be imaging during autoguiding Using the displayed red rectangle for the Autoguider chip in TheSky the Motion Controls in TheSky and by taking images using the Autoguider under the Autoguide tab in CCDSoft select and position a nearby moderately bright star in the Autoguider chip not near an edge of the image The star should be at about the same declination as the object you will be imaging during autoguiding Click on the Auto button under Use guide star at to let CCDSoft find the star A box will blink around the star Or instead of using Auto click on the star Click on the Calibrate button The telescope will be moved slightly in the NSEW directions and the resulting movement of the star in the image will be measured If calibration is successful you can proceed to the next step Otherwise it might have failed because the star moved off the Autoguider chip try again Try another star if you need to Now take Imager large chip images and Autoguider images until you find a position that will produce a good location of your object in the
6. Imager chip and allow for guiding on a star in the Autoguider chip The guide star should stand out against the noise with an exposure of about 5 seconds not have any pixel values over about 32000 5 second exposure should not be equaled in brightness by another star in the Autoguider image or just off its edge and not be near an edge of the Autoguider image Select a reasonable guide star exposure time e g a few seconds to avoid twinkling effects perhaps 5 seconds but longer if you need to use a dimmer star Take an Autoguider image to confirm the presence of the guide star in the image then click on the Auto key or on the star Click on the Autoguide button to start the autoguiding Observe the X error and Y error values they are in units of pixels When they drop to as low 1 0 you re ready to start imaging your object To image your object click on the Take Image tab in the Camera Control Panel select an exposure time binning and any other values you wish DON T use AutoDark that will close the shutter instead take a dark or set of darks later Then click on Take Image The imaging of the object using the large Imager chip is independent of the imaging of the guide star using the Autoguider chip 6 APPENDICES 17 When the object image exposure is done the autoguiding will still continue you can start another object image if you wish Indeed the best procedure might be to take
7. Observer s Guide for the Martin Observatory 14 inch Telescope John H Simonetti January 25 2012 1 Introduction This Guide outlines the basic procedures for running the telescope and collecting images using its CCD camera For more advanced use consult the pdf files of the manuals for TheSky6 and CCDSoft Version 5 available on the computer at the observatory and at Software Bisque s Documentation webpage The 14 inch telescope is computer controlled Virtually the only time you need to touch the telescope is to flip its on off switch Indeed since the tele scope s accurate pointing ability is sensitive to disturbances a good rule of thumb is Unless this guide specifically instructs you to do so DO NOT PHYSICALLY TOUCH THE TELESCOPE MOUNT TUBE CCD CAMERA FOCUSER CABLING OR OPTICS This also means you should not try to clean or adjust anything on the telescope including the optics If you follow this rule you will avoid most problems and the instrument should give you and others after you excellent performance If you encounter difficulties or are unsure of what to do at some stage don t hesitate to contact Dr Simonetti phone numbers are posted in the control building Better safe than sorry The 14 inch telescope is a Celestron Schmidt Cassegrain telescope mounted on a Paramount ME equatorial mount from Software Bisque SB Attached to the telescope is an ST 8E CCD camera from Santa Barbara Instr
8. S Time program if it is not already opened Click on ma Ne the Sync Now button and wait to see the program sync the PC clock with the received GPS time signal If the time and date make sense are not way off for some reason click on the Exit button If the time and date are way off and Sync Now does not seem to remedy the situation you can set the time manually by clicking on the clock icon in the toolbar at the bottom of the screen Create a folder on the desktop in which this night s images will be stored Choose a folder name like 2000 01 25 indicating the date of the observing session This folder may be deleted without notice soon after your observing so make sure you later copy all the files you want to a flash drive Observing groups in PHYS 3154 should put this night s folder inside a folder labeled by their group number Start JA Server double click on its desktop icon Make sure TheSky CCDsoft and AutomaDome applications are all active checked Click on the Start Applications button d A window TheSky Server will appear minimize it don t close it e Minimize AServer don t close it 8 Initialize dome control in AutomaDome a In AutomaDome establish communications with the dome Dome b Link Establish In AutomaDome initialize the dome Dome Find Home Au tomaDome should eventually reply Home Find Complete This could take up to 30 se
9. a set of images of not too great exposure to be averaged later That way you can get the benefits of a long exposure in the final averaged result without the possibility of losing the whole image if something goes wrong during a long exposure Also median combining the set of images will remove any cosmic ray hits If you are taking RGB images for later color combining you can switch filters and take another set of images etc 6 Appendices ST 8E CCD Specifications e 16 bit readout e Format 1530 x 1020 pixels unbinned e Pixel size 9 microns x 9 microns unbinned e Chip size 13 8mm x 9 2mm e Readout noise 15 electrons rms e Dark current 0 6 electrons second at 0 degrees Celsius e Gain 2 3 electrons ADU 2 3 electrons count e Exposure range 0 11 to 3600 seconds Saturation maximum pixel count with linear response about 16384 counts at high resolution you may find image values over 16 000 but the pixels are saturated in the full well capacity sense see below 65536 counts at medium low resolution Full well capacity 40 000 electrons high resolution 160 000 electrons medium low resolution Important Note Flat field images taken with our ST 8E at 3x3 low and 2x2 medium resolution may have a few scattered very low valued pixels and a few scattered very high nearly saturated pixels In this case images which have been flat corrected will display some very hot pixels These hot pixels are best remove
10. ble connector E to the Serial to PC port E on the Paramount Adapter Panel south side of the telescope mount Tighten the small screw on the top of the serial connector using the small screw driver sitting on the telescope pier s metal base plate connects the Paramount to the PC in the control building 5 Open the slit using the Slit Controller box on dome a Press OPEN or SCREEN on the control button box to the left of the Slit Controller The latter button opens both the slit and windscreen SCREEN may also be used later to open the windscreen after the slit 3 A TYPICAL OBSERVING SESSION A has been opened STOP will stop either motion in its tracks If it is at all windy and you will not be observing objects near the horizon it is useful to keep the windscreen closed the telescope may be shaken by winds reducing image quality Note the Slit Controller box should always be on showing a lighted red LED Don t turn it off when you shutdown 6 Start up the Dome Controller box to the left of the desk in the dome a Turn on the power use the rocker switch on left side of the Dome Controller b If there is possibly any ice or snow on the dome rock the dome back and forth very slightly to break any ice cementing the dome in place without straining the system too much c Close the dome door on the way out 7 In the control building start up the software a Start the GP
11. conds and the dome may even rotate all the way around Or it may only move a short distance Either behavior is normal 3 A TYPICAL OBSERVING SESSION 5 c Minimize AutomaDome 9 Establish communications between TheSky and AutomaDome a In TheSky program click on its title bar if necessary press the D keyboard key to open a Dome Controller Window b Establish communications in the Dome Controller Window Dome Link Establish c Close Dome Controller Window 10 In the dome prepare the Paramount telescope mount and CCD camera a Gently remove the telescope s lens cover being careful not to jar the telescope or touch the optics b Plug in the white AC adapter for the camera s parallel to ethernet box This white adapter is sitting on top of the pier s metal base plate It is best to plug this adapter into the outlet having the velcro strap and to strap the adapter in using the velcro strap c Plug in the Paramount s AC adapter a black rectangular box with three electrical prongs sitting on the telescope pier s metal base plate d Plug in the power cord for the CCD s power supply box mounted on the concrete telescope pier You should hear the fan on the CCD camera start up e Ground yourself then turn on power to the Paramount rocker switch on the South side of the equatorial mount head You should hear one short beep as the mount initializes it s RA axis and one short bee
12. cope Options Star Search menu item which allows the user to cause the telescope to move in an enlarging spiral pattern around its current location useful for finding a nearby relatively bright object TheSky presents a planetarium like view called the virtual sky in its main window You can use TheSky s Zoom buttons to magnify and de magnify the virtual sky Placing the mouse cursor on a button in TheSky will after a few seconds give you the name of the button White cross hairs show where the telescope is pointing A large white trape zoid shows the outline of the dome slit A red rectangle labeled ST 8 and lying at the center of the white cross hairs will show the field of view of the ST SE s imaging chip on the virtual sky you ll need to Zoom in to see this rectangle For this rectangle to be oriented correctly the Pole Up button must be clicked in when pointing the telescope to the west of the meridian thus North will be up When pointing the telescope to the east of the meridian the Rotate Tool button must be clicked to provide a tool for rotating the virtual sky so North 4 USING THESKY TO CONTROL THE TELESCOPE 10 is down in the display With these orientations set images displayed in CCD Soft will closely match the area outlined by the red rectangle in the virtual sky Also shown is the field of view of the ST 8E s smaller square autoguider chip a useful feature when setting up for autoguided imaging
13. d D sitting to the right of the PC connects the Paramount to the PC e Insert the connector for the yellow cable labeled E into the TCF S Hand Controller unit sitting to the right of the PC connects the TCE S focuser to the PC Insert the connector for orange cable F into port F on the back of the 3Com Hub TP16C sitting to the right of the PC connects CCD camera to PC 3 Power up the computer and monitors Wait for Windows to start up Login to the astro account 4 In the dome connect up various connectors handling the cables and con nectors gently and with care to prolong their lives and ensure good per formance a Connect together the two serial connectors labeled A sitting on the edge of the dome wall between the dome rotation motor and the desk connects the Dome Controller to the PC in the control building b Insert power plug B into the outlet B to the left of the desk power for the Dome Controller c On the north side of the pier near the floor plug the orange cable d ae C into port C on the SBIG E2P box connects the CCD camera to the PC in the control building On the north side of the pier near the floor plug the yellow cable D into the white connector D connects the TCF S focuser on the telescope to the TCF S focuser control box in the control room After grounding yourself connect the serial ca
14. d in the final images through use of a remove hot pixels tool in your processing software Such problems do not appear to happen when using high resolution flats taken with ST 8E For this reason high resolution might be the best mode to use when aiming for quantitative accuracy e g when producing images that will be used for precision photometry 6 APPENDICES 18 Start Up Summary for experts 1 Control room Check clipboard for updates Gently connect connectors plugs A B C D E and F Power up PC and monitors Login to astro account 2 3 4 5 6 Dome Gently connect connectors plugs A B C D and E Open slit Turn on Dome Controller Test for ice Close door on the way out Control room GPS Time Sync Now Check the resulting date and time Create desktop data folder AServer Start Applications TheSky CCDSoft and AutomaDome Minimize TheSky Server window 7 AutomaDome Dome Link Establish Dome Find Home 8 TheSky Hit D to open Dome Controller box then Dome Link Establish 10 11 12 Close Dome Controller box Dome Gently remove the telescope lens cover plug in white camera adapter Paramount and CCD camera Ground yourself turn on Paramount hear two single beeps Double click the joystick button sending telescope to Home po sition hear two sets of three beeps if not successful stop call pro
15. days of work done in setting up the telescope If you acciden tally click on either of these buttons select Cancel if when TheSky asks for your confirmation b If you click on the Slew button a box will appear asking you to con firm the slew and if you say OK another box will appear indicating Telescope slewing please wait Notice that in both boxes you have the chance to cancel the slew even after the slew has started If for some reason you made a mistake e g you suddenly realize the object is actually below the horizon click on the Cancel button no damage will be done and you can proceed as normal As the tele scope slews you can see the progress of the telescope in the virtual sky 4 USING THESKY TO CONTROL THE TELESCOPE 11 4 2 Slewing the Telescope to a Specific RA and Dec If you have an RA and Dec that you want to point the telescope to not an object then first read the above procedure Now instead of the above steps do the following 1 Hit the Z button to zoom out showing the full sky with zenith at the center and surrounding green area representing regions below the hori zon 2 Click on the Data Add User Data menu item In the Add User Data box with Data Class set to Objects Points and Object Type set to Refer ence Point click on the Add Entry button Enter your 2000 0 Equatorial Coordinates and click the Close button You should be able to find a red cross now displayed somewhe
16. dges of the images An ellipsoidal ring may also appear in the images if the camera has cooled quickly freezing moisture on in inner window surface The diameter of the ring may grow larger as the humidity decreases and eventually the whole image becomes clear of effects over the course of some minutes The part of the image inside the ring is ice free and usable 3 A TYPICAL OBSERVING SESSION 7 3 3 Shut Down Follow these steps in the order given 1 Terminate communications between TheSky and AutomaDome a In TheSky press the D key on the keyboard to open a Dome Controller Window b Terminate communications in the Dome Controller Window Dome Link Terminate c Close the Dome Controller Window 2 Close the slit and terminate computer dome control a In AutomaDome close the slit Dome Close Slit Alternatively you can press the CLOSE button on the Slit Controller box on dome Either way the windscreen will also be closed if necessary b In AutomaDome park the dome Dome Park AutomaDome will eventually respond with Park Complete c In AutomaDome terminate communications Dome Link Termi nate d Minimize AutomaDome don t close it 3 Take any remaining flat field images while pointing the telescope at the dome flat field screen inside the closed dome Remember to ground yourself before touching the telescope or its joystick The best position for the dome flat screen is on
17. e right in the displayed CCD image You can also try using TheSky s Star Search feature Telescope Options Star Search to find a target object just off the image Enter the field of view into the dialog box and hit the start button a speed of 4X seems to work nicely with continuous short exposures The telescope will slew in an enlarging spiral pattern around its current location If you are simultaneously 5 USING CCDSOFT TO CONTROL THE CAMERA 12 taking continuous short exposure images CCDSoft Camera Control Panel Focus Tools tab select Continuous any bright object you are searching for should eventually be apparent in one of the images Then click the stop button in the Star Search dialog Use the Motion Controls to center the object in your image 5 Using CCDSoft to Control the Camera To obtain one quality image of an object you need to acquire at least three images a light image or frame image of the sky object a dark frame and a flat field frame The latter two are used to correct the light frame The dark frame is taken with the same exposure time and CCD temperature as the light frame but with the shutter closed subtraction of the dark from the light frame removes the effects of dark current background level and noise effects The flat field frame is an exposure of an evenly flatly illuminated field using the same focus filter and any other optical conditions as for the light frame The f
18. est results take your flats for one filter focus before changing filter focus see next paragraph A set of flat field images is better than one then averaged which will reduce noise or best yet median combined which will also remove all cosmic ray hits You should set Reduction under the Take Image tab to AutoDark when taking these flats so they are dark corrected If you do take dome flats with one focus filter before changing focus filter for further imaging of the sky follow this procedure 1 In the dome close the slit use the CLOSE button on the Dome Slit Con troller only if there is any strong outside lighting e g the Moon that will enter the dome telescope Position the dome flat screen as usual use the East and West buttons on the Dome Controller box and after grounding yourself use the Paramount s hand controller to point the telescope at the flat screen Arrange the illumination source appropriately 2 Proceed to take the flat field frames using CC DSoftas described in the paragraph above 3 To go back to imaging the sky first turn off the illumination source in the dome and if necessary re open the dome slit OPEN button on the Dome Slit Controller 4 Once you slew to an object using TheSky the dome will reposition itself so the slit coincides with where the telescope is being pointed 5 4 Autoguide Tab Autoguided Imaging Images of more than a few minutes may show tracking errors stars will
19. f Turn off lights Close door on the way out Control room Gently switch ON the TCF S Hand Controller TheSky Telescope Link Establish If not successful stop call prof CCDSoft Ctrl W click Connect click Temperature set to Recommended Set point unless it is very cold Shut Down Summary for experts 1 ts CR aS D 10 TheSky Hit D to open Dome Controller box then Dome Link Terminate Close box AutomaDome Dome Close Slit Dome Park Dome Link Terminate Take any remaining dome flats TheSky Telescope Options Park If not successful stop call prof TAServer Exit All Applications Don t save any changes to Normal sky if asked Close AServer Gently switch OFF the TCF S Hand Controller Dome Put dome in park position orange markers Turn off Dome Controller Ground yourself turn off Paramount Unplug Paramount CCD camera and camera s white adapter Gently replace the telescope s lens cover Gently dis connect connectors plugs A B C D and E Lights out lock door Control room Copy files to flash drive Shutdown PC and monitors Call prof s office Gently disconnect connectors plugs A B C D E and F Check thermostat gt 55 F Collect and remove trash Lights out lock door Close and lock gate on way out Drive home safely
20. ht star not too dim not near saturation Get into the Focus Tools tab 5 USING CCDSOFT TO CONTROL THE CAMERA 14 in the Camera Control Panel set an exposure time of at least a few seconds to average out twinkling and atmospheric seeing effects and take continuous images Look at the Cur Sharp value Current Sharpness which is a measure of focus the larger the better and look at the images Adjust focus using the focus controls in the Focus Tools tab while watching the images and the sharpness value The In and Out focus control buttons move the TCF S focuser in and out duh selecting Large or Small will make the In Out buttons produce a change in the focus position value of 200 or 50 respectively The Move To button allows you to select a focus position value to move the TCF S to The range of possible focus position values is 0 all the way in to 7000 all the way out The focus position value is displayed in a box just to the right of the In Out buttons and on the TCF S Hand Controller By the way with CCDSoft connected to the TCF S the Hand Controller s IN OUT buttons will not control the TCF S focuser you will only be able to control the TCF S using CCDSoft Furthermore do not adjust any other switches on the Hand Controller Refine focus in 1x1 binning mode Note the focus value number for future reference CAUTION Be careful in using the Focus Control To find focus with ou
21. lat field frame is used to correct the light frame for effects due to systematic and random variations in the imaging system s sensitivity e g an off axis decrease in effective aperture of the telescope For more details see your favorite reference on CCD imaging In this section we will simply refer to light dark and flat field images without further explanation This section describes how to control the camera using CCDSoft Version 5 All camera operations are accomplished using the Camera Control Panel in CCDSoft Camera Setup or Ctrl W In short if you will be using the currently selected filter you are already focused for that filter you understand what sort of images you want to collect and you won t be autoguiding then for basic imaging you will only need to 1 Take an image s using the Take Image tab where a Exposure time is set to between 0 11 and 3600 seconds 60 minutes b Series of value is set to 1 for taking one image or gt 1 in which case make sure To new window is checked or set up for automatic saving of the images under the AutoSave tab c Subframe is usually left Off which means use the full chip d Bin or resolution is set to 1x1 for high resolution no binning of pixels 2x2 for medium resolution one image value per each group of 4 chip pixels or 3x3 for low resolution one image value per each group of 9 chip pixels and even more drastic binning is possible e Frame is set to
22. p as it initializes its Dec axis f Ground yourself then double click the button on the top of the Paramount s joystick The telescope should slew to it s Home po sition HA 2 hours Dec 0 degrees and then emit three beeps for each axis If it does not contact the professor g Turn off the lights in the dome as you leave so observing can begin Close the dome door 11 In the control building gently turn ON the TCF S focuser using the switch on the Hand Controller unit Its display should show TCFS then the version number of the hardware then eventually the focus position value number will move to some nonzero value Do not adjust any of the other switches on the Hand Controller 12 Establish communications between TheSky and the Paramount a In TheSky establish communications Telescope Link Establish 3 A TYPICAL OBSERVING SESSION 6 b Wait and watch Eventually white cross hairs should appear in TheSky s virtual sky display indicating the direction the telescope is pointing and indicating that communications have been established with the telescope 13 Establish communications between C CDSoft and the ST 8E CCD cam era a In CCDSoft open the Camera Control Panel Camera Setup or Ctrl W b Click on the Connect button to establish communications c Wait and watch Eventually the Status at the bottom of the Panel will inform you that you have a link to the Imager d
23. r filters you won t need to move the focus tube very much stick with the Small focus control setting If you are in doubt as to what s happening or inexperienced in setting the focus have someone in your group watch the action in the dome while you control the focus from the Control Building and communicate 5 2 2 Manual Focusing Using the Hartmann Mask You may use the Hartmann mask for focusing the cardboard Hartmann Mask contains two small holes and is put on the front of the telescope If the image is out of focus you will see two images for the star With the Hartmann mask in place adjust the focus until the two separate images of a star merge The holes are triangular and will therefore produce diffraction spikes one set for each hole You may need to adjust the displayed images s Background and Range values to clearly see the spikes When the two sets of spikes coincide point to the same center location you have reached focus Repeat the process at higher resolution to refine your focus Note the focus value number for future reference 5 2 3 Automatic Focusing Using Focus If you are anywhere near focus as you should be for any of our filters using Focus should home in on an accurate focus automatically Details are available in the pdf file of the CCDSoft Version 5 User s Manual see the shortcut to the manual on the PC desktop Click on the Focus button popping up the Focus Setting box Se
24. re in the virtual sky at your entered RA and Dec 3 If the red cross is above the horizon you may proceed Otherwise you should not slew to these coordinates Stop Now 4 If the red cross is above the horizon click on the cross to bring up this point s Object Information box The point should be labeled as something like Buffer Point 1 in the Object Information box Check it s altitude and if it s above the horizon you may click on the Slew button green telescope to slew to this point 5 Zoom in hit the Pole Up button i e set the orientation properly etc 6 You may at any time delete all such user points by clicking on the Data Add User Data menu item then hitting the Remove All button 4 3 Centering an Object Once you start taking images your target object may not actually be centered or it may possibly be outside the field of view You can use the Motion Controls dialog box to center your object Telescope Motion Controls menu item Select Jog and Ra Dec in the Motion Controls dialog box and you will be able to reposition the telescope North South East or West by small quantitative increments The CCD camera is oriented on the telescope so that CCD images for sky locations with positive hour angles i e West of the meridian have North up and East to the left as displayed in CCDSoft When the telescope points to locations with negative hour angle North is down and East to th
25. rted and working otherwise the telescope s pointing model may be lost A convention used in this guide a program menu item such as Save As under the File menu in a program is written as File Save As 3 1 Start Up You should turn on the stairway lighting at the bottom of the stairs leading up to the observatory when you arrive it should be turned off after climbing the stairs to the deck You should have the deck lighting on during the start up and shut down procedures but you should turn off all outdoor lighting during observing Follow these steps in the order given 1 In the control building check for notes on the clipboard near the com puter concerning updates to the telescope start up shut down or usage procedures 2 Gently connect up various connectors handling the cables and connec tors gently and with care to prolong their lives and ensure good perfor mance 1The focal length field of view and the angular size of pixels have been determined em pirically 3 A TYPICAL OBSERVING SESSION 3 a Insert power plug A into wall socket A to the left of the PC monitors b Insert power plug B into extension cord B to the right of the PC enables power for all components in the control building c Connect together the connectors labeled C sitting to the right of the PC connects the Dome Controller to the PC d Connect together the connectors labele
26. t Sam ples to 10 Averaging to 1 and Initial Direction to what you think will head toward correct focus perhaps as determined by a quick attempt at manual 5 USING CCDSOFT TO CONTROL THE CAMERA 15 focusing even choosing the wrong Initial Direction will eventually work just taking longer Hit OK when ready Watch the images of the star and the sharp ness value as Focus finds focus Verify the focus by examining a full image Note the focus value number for future reference 5 3 Taking Flat field Images Good flats can be taken using the dusk or dawn sky sky flat or the white screen attached to the inside of the dome dome flat at the end of an observing session In any case the goal is a moderately short exposure of a flatly illuminated field of view with resulting pixel values at about 1 2 of the saturation for the resolution you are using Saturation is 16384 at 1x1 resolution 65356 at 2x2 and 3x3 The exposure should be more than just a few seconds to avoid shutter movement effects but not so long as to collect many cosmic ray hits try for something like 10 15 seconds Illumination for the dome flats is best done with a not too bright light e g a flashlight and a large white cardboard shining the light onto the white cardboard and allowing it to reflect up onto the dome screen You want the filter and focus geometry exactly as when your object images were taken remember those focus value numbers For b
27. the West side of the observatory use the LEFT and RIGHT buttons on the Dome Controller box to position the screen 4 In the control building park the telescope terminating communications between TheSky and the Paramount a In TheSky program park the telescope by using the Telescope Op tions Park menu item Click OK in the box that asks if you really want to send telescope to its park position Wait until the process totally ends it could take a few moments but ultimately the hourglass cursor changes back to a normal cursor and the green telescope button becomes lit This process also automatically ter minates communication between TheSky and the Paramount If the telescope does not park the green telescope does not become lit there s a problem stop and call the professor Do not turn off the Paramount without first getting it to Park in TheSky 5 Exit all applications using A Server a In AServer click on it s Exit Applications button to exit TheSky CCDSoft and AutomaDome 3 A TYPICAL OBSERVING SESSION 8 b c Say No in any dialog box popped up by TheSky asking if you want to save changes to Normal sky Close AServer 6 Turn OFF the TCF S focuser using the switch on the Hand Controller unit 7 In the dome secure the telescope and dome a b PS rra A a S wm _ gt m Oo YN a i k Is the dome slit actually closed
28. then turn off the monitors A PHYS 3154 observing group should now call the professor s posted office number and leave a message on his phone reporting on the suc cess or whatever of the night s observing This way the Observatory Schedule can be updated before noon of the next day 4 USING THESKY TO CONTROL THE TELESCOPE 9 d Gently disconnect connectors plugs A B C D E and F e Make sure the thermostat is set to at least 55 degrees F Collect and take with you any trash you generated during your use of the observatory g Turn off any lights including the light outside above the control building door h Lock the door on the way out But first make sure you have the keys i Turn off all deck lighting Turn off the stairway lighting at the bottom of the stairs Use your flashlight to get to your car j Close and lock the gate at the entrance after you drive out 4 Using TheSky to Control the Telescope This section describes 1 The Find button binoculars and resulting Object Information box containing object location information with Slew button 2 The Data Add User Data menu item which allows the user to enter RA and Declination coordinates for a point which can be the target of a slew 3 The Telescope Motion Controls menu item which pops up a box containing buttons to move the telescope small distances in the N S E W directions 4 The Teles
29. ument Group SBIG in combination with an SBIG CFW 8A motorized filter wheel Focus ing is done using an Optec TCF S Focuser Present in the optical path is an Optec NeztGEN WideField 0 50X telecompressor which halves the standard focal length of the telescope doubling the width of its field of view The dome is equipped with hardware from Meridian Controls Corporation Telescope cam era and dome control are accomplished using SB s TheSky CCDSoft and Au tomaDome software running on a dual monitor Windows XP computer Flash drives can be used for image transport 2 BASIC SYSTEM SPECIFICATIONS 2 2 Basic System Specifications Focal length 2 14 f 6 0 e CCD format 1530 x 1020 pixels unbinned e Pixel size 9 microns x 9 microns or about 0 87 arcseconds x 0 87 arcsec onds unbinned e Field of view about 22 arcminutes x 15 arcminutes long axis is oriented approximately E W on the sky Filters B V and R Bessell broadband photometric filters 3nm bandpass Ha filter clear no filter e Exposure range 0 11 to 3600 seconds e CCD linear saturation level about 16384 counts unbinned 1x1 65536 at 2x2 and 3x3 binning 3 A Typical Observing Session This section lists the steps taken during a typical observing night The order of the start up and shut down steps is very important For example the Paramount should not be turned on until it s clear that the PC is on and working and TheSky software is sta
30. you save it to disk regardless of what file format you use SBIG or FITS for example Another note the time recorded by CCDSoft in the image file is the start time of the exposure For some applications e g observations of asteroid positions it is the middle time of the image that is desired just add half the exposure time to the start time to obtain the middle time of the image The default time recorded in the image files is UTC not EST or EDT 5 1 Take Image Tab Filter Choice Select the filter you want to use in the Filter choice displayed under the Take Image tab of the Camera Control Panel Note refocusing will probably be necessary after each change of filter see the subsection on the Focus Tools tab below The photometric filters can be used to make color images processing beyond the basics is necessary The B filter passes blue light V passes green and R passes red therefore standard RGB color images can be made 5 2 Focus Tools Tab How to Focus Focusing a CCD camera can take longer than you might think but once the camera has been focused on a star it will be in focus for that same filter for any other object you image At the 14 inch there are a few methods you can use to focus 5 2 1 Manual Focusing Start with 3x3 binning if you re way out of focus e g you see donuts in a 3x3 image instead of stars Take an image Draw a box around a moderately brig
Download Pdf Manuals
Related Search