Taking an Image

Before taking a picture you should check that filter is in the proper position. For example, if you want to use the V filter, you will type:

pfilter V

To take a picture with a 10 second exposure time type:

 image time=10

It will then write a FITS file in the current working directory with the name image.fits You can use the tv command or ds9 to display it. ZEROING (SYNCING) THE TELESCOPE If you find that the telescope is consistently pointing off from the center of the CCD in a consistent manner you can adjust the telescope pointing constants to make the centering better using the following:

* use the tx point .. to point to known star * use the tx offset .. to center the star * type tx zero last

This will adjust the values of the additive pointing constants cra and cdec to give better pointing.

Note: ideally these constants are near zero degrees. SOME OTHER THINGS

* tx help - will list all the telescope server commands * tx xxx help - to list options of the xxx command * tx focus mm=-6.1 - will set the telescope focus position to -6.1 millimeters * tx offset dec=.01 ra=.01 cos - will move the telescope .01 degrees in dec and ra * tx dome center - will ensure the dome is still looking out the slit * tx where - will show where the telescope is pointing * lst - will print out the current local sidereal time

TROUBLE SHOOTING You can view the finder telescope as VIDEO 2 in with the axis video server the login is the usual anonymous/guest. The finder image can be converted into a FITS file using the fimage command. It produces a file fimage.fits which you can inspect with your favorite tools. The star should be on finder pixel row=177 col=335 when centered on CCD.

If you want to look at the telescope turn on the room lights type:

tx interlocks lamp=on

I leave it as an exercise to figure out how to turn them off.

Other things to check:

* Is the slit open? .. tx slit * Is the dome centered? .. tx dome center * Is the guider in the way? .. tx stage x=0 y=0 * Is the telescope still tracking? .. tx track * Is the mirror open? .. tx mirror * What filter is in use? .. pfilter

CLOSING DOWN THE OBSERVATORY When you are done observing for the night type:

closedown

Then close down your windows.

Instructions Index