Perkins Telescope Guide by Melissa Hayes

Last altered June 17, 1999

This guide provides a rough outline for setting up the Perkins 72" telescope and beginning observations. It assumes that you are performing each section in the order listed. If the instructions tell you to perform a command, but do not specify which computer to use, use the WC.


1Initial Setup

Do the following tasks, in this order:

  1. Turn on telescope main power, located on the console in the dome

  2. Fill the liquid nitrogen dewar

  3. Turn on rack power, in the control room

  4. Put the dome in its proper position with the hand paddle. The black arrow in the dome and the black vertical stripe on the wheel below it should be in the area designated with the black stripe on the wall. This is just above the stairs into the dome.
Start the computers in this order:

  1. IC - type "2"

  2. MOVE - login with username and password listed on the wall in the control room; say "g" to use the guider; do the paddle and dome initializations as instructed; say "y" to using previous coordinates

  3. On the Sun workstation, login with the same username and password. Create a directory on the Sun in /perkins/data/pcdata. This corresponds to directory e: on the WC.

  4. WC - type "2", then "y", then hit return

2Taking Bias Frames

  • Set the CCD shutter control to the closed position (middle position). This is a silver switch on the CCD, near the temperature readout.

  • Leave the dome, mirror cover, and instrument cover closed.

  • Set up the TCCD program on the WC:

    • Type "+disk" and "+store"

    • Select your binning size, such as "2x2"

    • Set the directory and filename to store images to: "filnam e: \ directory \ filename.001" (Note: e: on the WC corresponds to /perkins/data/pcdata on the Sun.)

    • Set the observers name with "observers joe, john"

    • Set the telescope with "sett Perkins 1.8m"

    • Set the instrument with "seti 2:1 f/17 direct" for the SITE CCD

  • Set to bias frames with "bias bias"

  • Take an exposure with "go" (Note that the previous command sets the exposure time to 0 seconds.)

3Taking Dark Frames (After Biases)

  • Set to dark frames with "dark dark"

  • Set the exposure time with "n seconds"

  • Take an exposure with "go"

4Taking Dome Flats (After Darks)

  • Open the mirror cover. This is a silver switch, unmarked, on the back of the mirror. You will be able to hear and see the covers opening.

  • Open the instrument cover. This is a set of two blue buttons under the lip of the autoguider box. Hold the inner blue button down until an orange light comes on. You will not be able to hear or see anything else.

  • Set the CCD shutter control to computer control, which is the up position.

  • Turn on the dome flat lights. These are controlled on a silver panel on the back of the mirror. There are instructions on the panel to follow. Select broadband.

  • In MOVE, do "dm" to turn on dome following, then "fs" for Flat Screen. The dome and telescope should move appropriately.

  • Check that the telescope is centered on the flat surface. If not, center the telescope with the hand paddle.

  • In MOVE, check that the guider mirror is out of the way by doing "gst" for Guider STow.

  • On the WC, set to dome flats with "flat dome flat".

  • Choose the filter with "n filter"

  • Set the exposure length with "n seconds"

  • Take exposures with "go"

5Taking Sky Flats (After Dome Flats)

  • Turn off the flat lights.

  • Close the mirror cover.

  • Open the dome. The button for this is on the rim of the dome, under the black arrow. If it is freezing outside, open the dome entirely, then back it up slightly.

  • Open the mirror cover.

  • In MOVE:

    • Move to the Uniform Illumination sky area with "ui"

    • Enable tracking with "tr"

    • Enable dome following with "dm"

    • If you did not do dome flats, ensure that the guider mirror is out of the way with "gst".


  • Set to sky flats with "flat sky flat"

  • Choose a filter with "n filter", where n is the filter number. These are listed on the whiteboard in the control room.

  • Set the exposure length with "n seconds"

  • Take exposures with "go"

6Observing an Object (After Sky Flats)

  • Focus the telescope.


    • In MOVE, goto a star, using "co", which will ask for RA and DEC coordinates.

    • Using the hand paddle, set the focus about 50 units above the approximate correct focus, which is probably about where it is currently set. The focus readout is on the rack, above the autoguider TV. Note the beginning focus number.

    • On the WC, do "focrun". When this is finished, note the ending focus number.

    • From the mosaic image, choose the image with the best focus. The only asymmetric image was the first one taken, and then a U pattern is followed with the subsequent images. Interpolate the focus the best image had. Set the focus to this number with the hand paddle, approaching the focus from a higher number.

  • Orient the guider. These steps are in MOVE.


    • Move the guider to the center of the field of view with "gho", which is Guider HOme.

    • Using the hand paddle, place the star in the upper left corner of the guider screen.

    • Orient the guider with "gos". Watch this process and read what is going on in MOVE. If everything seems to go OK, do NOT zero the offsets.

    • Stow the guider with "gst", which means Guider STow.


  • Point the telescope at the object. These steps are in MOVE.


    • Go to the object by specifying its coordinates. Use "co hh mm ss; dd mm ss" to enter RA in hours minutes seconds and DEC in degrees arcminutes arcseconds. There are many other ways to locate an object; see the MOVE manual.

    • MOVE will tell you where the telescope is going and confirm the move. Go into the dome and WATCH THE TELESCOPE SLEW. If the telescope looks like it's going to run into something, hit a button on the hand paddle or a key on the MOVE keyboard.

    • Find a guide star with "ggs", which is Guider Guide Star. Follow the instructions. The guider can easily follow stars up to 11.5 magnitudes.


  • On the WC, name the object with "object nameofobject"

  • Choose a filter with "n filter"

  • Set the exposure length with "n seconds"

  • Take exposures with "go"
To observe the next object, the guider does not need to be re-oriented.


7Closing Up the Telescope

  1. On the WC, type "bye"

  2. On the IC, type "bye"

  3. In MOVE, move the telescope home with "ho", then quit with "qu". MAKE SURE YOU QUIT WITH "QU".

  4. Turn off the rack power.

  5. Close the instrument cover. This is the outer blue button. When the cover is closed, an orange light will come on.

  6. Close the mirror cover, then the dome.

  7. Fill the liquid nitrogen dewar.

  8. Turn off main power.

8Odds and Ends

Here are some helpful tips and shortcuts.

To do multiple exposures of the same length in a row, on the WC do "n mgo", where n is the number of exposures to take.

The MOVE computer starts up in the equinox of the current day. To set this to something more convenient like 2000.0, in MOVE do "ne 2000.0", then "ex". Everything on the MOVE screen will then be in the new equinox and MOVE will expect you to type everything in in the new equinox.

If you have a list of standard objects, you can make a list of them in MOVE so that you don't have to keep typing in their coordinates. Here's how (these steps are all in MOVE):

  • Do "rt" to turn off the remote.

  • Do "ol" to create a new Object List. Follow the instructions and enter the appropriate items.

  • Do "rt" to turn on the remote.
To access this list in MOVE, do "of listname" to open the file. Do "rf \mbox{objectnumber}" to read the coordinates of the object. The objects are numbered in the order they were entered. To edit the list, turn off the remote, do "ol listname" and follow instructions, then turn on the remote. You will not lose the file when MOVE is turned off.

You can also point at an obect in MOVE with "og objectname" (for Object Go), where objectname is a Messier object, an NGC object, an HR star, or a few other catalogues.

You can point the telescope to an object done previously that session with the "pm" command in MOVE. "pm" presents a list of previous coordinates to choose from.

To move the telescope to the zenith, in MOVE do "ze".

Occasionally, you may see on the display screen that the object is not centered properly. This can be fixed on the WC. First do "15 15 setp" to set the correct plate scale. Then do "locate". A cursor will appear on the display screen. Use the mouse to place the cursor on the point on the screen you wish to move (it needn't be an object). Then hit ESC. Then move the cursor to where you wish the point to be and hit the RIGHT mouse button. This will move the telescope slightly as you indicated. You should turn off guiding when doing this, or the telescope may lose the guide star.

You can slew the telescope in small amounts by direction from the WC, such as "n north", where n is the number of arcseconds to move north.

You can focus the guider in MOVE with "gfo". You can change the black level of the guider display in MOVE with "gbl".

To change the extension number at the end of a filenams, do "n newext", where n is the new extension number.

There are two hand paddles that can move the telescope and the dome, as well as a few other things. One is hanging on the console in the dome near the main power switch. The other is in the control room. If MOVE is not currently running, these paddles will not work.

If you need to abort an image while it is integrating:
  1. On the WC, hit shift-s. When the WC asks if you wish to save the image, hit ``n''.

  2. On the IC, hit return. Then do ``recover'' and then ``remote''.

  3. On the WC, to clear the CCD, do ``1 seconds'', then ``go''.

  4. On the IC, hit return.
At this point, things should be back to normal.


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