Observing Checklist for Imaging
with the 24" Telescope and ST9 CCD
Using CCDObs (Windows PC)

Linux commands are shown in italics.
Commands in the ucirob program (Linux PC) are in red.
Commands in Xephem/SkyView (Linux PC) are in green.
Commands in the CCDObs program (Windows laptop PC) are in blue.

  1. Take the grey-colored cap off the telescope baffle, which protects the instruments from dust.
  2. Log onto ucirob.ps as observer. Before you start ucirob, the computer-controled AC power unit should be cycled on/off. That's the red-lighted power switch beside the large connector on the front of the black box in the middle of the rack. Start ucirob, the observatory control program, by doing 'ucirob &'. Open the observatory with Open Obs and when completed (see message screen) make sure the mirror covers are indeed all the way open. If not, open the cover gently with your hand. 
  3. Power up the Windows PC, in which you will use the CCDObs program to control the CCD. If it isn't already plugged in, plug the USB cable labeled ST9 into the laptop. Start the CCDObs program.
  4. On the Windows PC, create your own subdirectory for that night in which to store your images. Start your entry in the Observatory Log Book noting the directory where your  images will be stored.
  5. Start Xephem (FILE/Start Xephem).
  6. Open the SkyView window in Xephem (View/SkyView ).
  7. The scale button on LHS menu changes coords to RA/DEC in SkyView.
  8. Toggle Live Report (top button on RHS) to get cursor readout of RA/DEC.
  9. Once the observatory is open, in Xephem 's SkyView bring up the Telescope/Configure panel, and it should read "lx200xed" and "queue". Click on Show Sky View Marker. Click on Running. Then click on OK in the status window at appears -- don't forget to do this because it completes the link between Xephem and ucirob.
  10. Plot the CCD Field-of-View in Xephem's SkyView by: (1) pulling down Control -> eyepieces - > ST9 (or whatever CCD it is), click Use then close the window, and (2) right click and select Place Eyepieces.
  11. Check the pointing of the telescope. In SkyView, put the cursor on a very bright star (e.g., Deneb, Vega or Arcturus) and right click to get information on it.  Right click, and hold down right button to Center and Zoom on the object.  To slew the telescope to it, right click, hold the mouse button down, and slide to Telescope GoTo.
  12. Power up the CCDs (CCDs button) in ucirob. Wait a minute then click on the Establish Link button in CCDObs. You should see the status of the CCD in the lower right corner of the window. Next set the operating temperature of the CCD (degrees Centigrade) by clicking on the Setup button. Set the Setpoint to no more than 25 degrees below ambient or frosting will likely develop on the CCD window, and turn the Temperature Regulation to Active. Check that the power doesn't exceed 80% once the operating temp is reached. If it does you must raise the temp. If the dessicant in the camera has not been baked lately, the CCD window may frost over if the humidity is high and the operating temperature is low. You'll notice it as a large-scale pattern on the CCD image, similar to fog on your bathroom mirror. If frost occurs, raise the temp (turn off temp reg) and take images until you find a temp that works. Remember the lower the operating temp is the lower the dark count and noise will be.
  13. Make sure the instrument selector is set to CCD. Take a test image with Grab to verify the ST9 is working and the pointing is good. 
  14. If you want to use the Finder Scope:
  15. If you need to tweak the centering of the star in the ST-9 CCD FOV, move the telescope by entering offsets in RA and DEC in the ucirob window (see the field sized and orientations below). If this star was near zenith and you had to move significantly to get it centered on the ST-9 frame then you should Reset Home Coordinates in the ucirob window. But don’t do this if the star is far off zenith because this error may simply be due to inaccuracies of pointing and slewing.
  16. Field Sizes and Orientations:
    1. ST-6 FINDER CCD: North is Up, East is to the Left with the origin at top, left-hand cornor of the display. Note that there are two bad pixels that lie at (x,y) = (221, 168) and (239, 108). Do not confuse them with stars.
    2. ST-9 Science CCD: FOV = 6.9' x 6.9'. North is Up, East to the Left with the origin at the top, left-hand cornor of the display.
    3. ST-9 TrackingCCD: FOV = 2.6' x 2.2'. North is Up, East to the Left with the origin at the top, left-hand cornor of the display. The Tracking CCD is located due South of the Science CCD.
    4. 40mm EYE PIECE: center of the ST-9 FOV is approximately one third in radius outward from the center of the eyepiece FOV roughly along the x-axis
  17. If using the finder scope: if you need to reset the default center of the ST-9 FOV on the ST-6 finder image then place your cursor on an object in the finder image that currently lies at the center of the ST9 image, Left Click on the object, which displays the star’s x,y centroid and hwhm (although  hwhm is incorrect), then click on ST-9 Center.  Turn the ST-9 Frame off and on to redraw the frame at the new center. Note that the current default ST-9 center is (x,y) ~ (200, 100).
  18. Once the telescope is centered on the sky, you might want to check the location of the star in the eye piece field of view (remember to use the instrument selector in ucirob to move the flat mirror back and forth between the ccd and eye piece positions). Also, you can check to see where the star falls in the field of view of the smaller black-colored finder scope that’s attached to side of the 24” telescope. If the star isn’t centered in the FOV then tweak the set screws so that it is. Often people jog it out of alignment by bumping into it. Note how much fainter the star appears in this small finder scope compared to the 24”. However this finder can be very useful, because it has the largest field of view. If the telescope’s pointing is very far off (for example if you’re trying to point to a planet at very low altitude) this maybe the most useful finder to use to correctly center the telescope on your object.  
  19. Focus the telescope for the ST9 CCD by pointing to a ~5th mag star near where you want to take your science images. Set the camera to the V filter, because when the camera powers up it maybe in the "U" position which means there is no filter. Take a series of images of the star at different focus settings and measure the FWHM and Peak Flux for each to find the best focus, i.e. the focus setting that gives the smallest FWHM, highest Peak Flux, and the roundest profile. Find a star bright enough to record > 1000 ADU at peak in a ~3 sec exposure. Note that you can change filters to increase/decrease fluxes (all the filters are parfocal). The minimum time of 3 sec will allow you to sufficiently average over temporal variations in the seeing caused by the atmospheric fluctuations. Use a focus step size of  ~15 units, and plan to try 5 to 7 focus values.  Step through focus values monotonically (either always decreasing or increasing) because there is some backlash in the motors when you change directions, and hence you want to avoid it. Under Telescope/Change Focus, enter a new focus value for the T Axis and click Move. Leave the TUV axes linked so that all three motors attached to the secondary will move by the same amount. (You would only unlinks them to change the collimation of the secondary mirror, but this should only be done by one of the professors!) Take an image with the ST9 with Grab. Click XHair then left click on the star. Record the FWHM, flux, and apparent roundness. Repeat for the series of focus values and determine the best focus. Move the focus to ~75 units above/below the last used best focus (consult the CCD Logbook) and then back down/up to the best focus (to mitigate errors due to backlash). You may have to refocus periodically if the temperature changes greatly or as you move to different locations in the sky. As the temp decreases you will have to move to smaller absolute values of the focus (~10 units/1 deg C decrease in T). Currently the Best Focus is T = -4376, U = -3143, V = -4526 for the ST9 CCD for T = 17 deg C when recollimation was last done in Nov, 2007. Typical values at best focus FWHM = 3.5 pix.
  20. Next move the telescope to your science target. In Xephem, you can right click on an object and while  holding down the mouse button scroll to Center+ Zoom  thenTelescope GoTo. Take an image to make sure you're target is positioned well on the CCD.  In not, you can move the telescope using ucirob to center it.
  21. There are two ways to guide the telescope while exposing on your science target. Using the AO7 + ST9 Tracking CCD is preferred because the pixel scale of the Finder Scope + ST6 CCD is very course:

Shutting Down the Observatory

  1. Turn of the temperature regulation for the ST9 and shut it down (in CCDObs do Setup then Close Link and edit CCDObs, or in CCDAuto do CCDAuto/Cameras/Imaging CCD/Turn off temp reg, Close Link then File/Exit).
  2. If you used the Finder Scope + ST6, under Finder/Settings turn off temperature regulation.
  3. Under Power Up turn off the CCDs.
  4. In Xephem 's SkyView bring up the Telescope/Configure panel.  Click on Running to disconnect link between Xephem and ucirob.  If this is not done, then the next time the telescope is used Xephem will not be able to send movement commands to the telescope.  If this is was not done the last time the telescope was shut down, the computer will need to be rebooted (following the directions below).
  5. Exit Xephem.
  6. Close Obs in ucirob.
  7. Exit ucirob.
  8. Put the grey-colored cap on the baffle.
  9. Log off the computer and turn off the monitor, but do not turn off the computer. We leave it on so that anyone can log in remotely from any unix machine and operate the telescope.
  10. If something goes wrong, call Profs. Smecker-Hane. Do not leave the telescope/ucirob if you are not sure the shutter is closed for the night!


Important Contacts:

If you run into a problem, you can call Profs. Tammy Smecker-Hane (824-7773 @ work, 509-7195 @ home).

If you need to reboot ucirob:

If ucirob crashes you may need to reboot the machine. You can't simply reboot the computer because the computer will be sending random signals to the rack. If you do, you're likely to get random motion of both the shutter, dome and lights! Instead follow this sequence:

  1. Turn off the power to the rack (red button on top of rack) and turn off the power to the AC controllable outlet box (red button on the middle box in the rack) .
  2. Reboot the computer.
  3. Enter ucirob, which will set the state of the electronic input to the crate. Then exit ucirob.
  4. Turn the rack and AC controllable outlet box back on.
  5. Restart ucirob. Send the dome to the home position (Observatory/Send Dome Home) to make sure it is properly initialized.

T. Smecker-Hane

UCI Observatory

Last updated on 11/10/07

Department of Physics & Astronomy