This document describes the basics of the use of the 40-inch for CCD imaging. It is recommended that it be read in its entirety before the observing run commences.

1  Before you start

Some things which should be done early in the afternoon before you start your run:

1. Check that the CCD/Dewar you want is on the telescope and is cold.
2. Check that the LN₂ dewar is in the dome and full enough to do a couple of fills. If it is Friday it will need to last over the weekend. Hold times for the large dewars is 18-22 hours, the smaller ones hold for up to 12 hours.
3. Check that the filters that you need have been installed in the filter wheel in their correct positions.
4. Check that you can run CICADA (see Section 3) and can write files to the data disk.
5. Make sure you have tapes and can write to them with the tape drive.
6. Check that the CCD sees light. Verify that the gain and readout speed is what you want and that the bias levels and RON are reasonable (bias is typically 600-1200 ADU).
7. Check that the telescope computer and TCS is running and reading the coordinates.
8. Check that you can move the telescope. (see Section 2). Check that when the telescope is tracking and you do an exposure that the FILTER and RA and DEC are written to the fits headers of your files.

In all cases, if you have problems - contact the technicians as early as possible.

2  Starting up and using the telescope

3  Starting up and using Cicada

4  Shutting things down

Once your flats and biases are taken:

1. replace the telescope lid, and close the dome slit.
2. TURN OFF THE TRACKING so the telescope doesn't run into the floor.
3. fill the CCD dewar so you don't have to get up just to fill it before the vacuum is degraded.
4. write in the weather log book, and dim the lights.
5. submit any faults to the so the technicians can work on it during the morning.
6. watch the sunrise, go to the lodge, and go to sleep.

5  General Tips about observing with the 40''

6  Troubleshooting

Loud alarm goes off while slewing

You've slewed past the RA axis limit.

1. Hit alarm off button (the sound yet won't stop yet)
2. Hold down the top of the horizontal limit button while
3. slewing in the direction opposite to what got you in trouble in the first place. Once the telescope is back within the limits, the alarm will stop.

Dome won't rotate

Dome being domes, get stuck sometimes.

1. Try rotating the dome back in the opposite direction until it gets unstuck, then try again.
2. If the dome is completely stuck, the circuit-breakers might have tripped. To check, try the flourescent switch under the dome shutter - if the lights don't go on then you have to reset the circuit breakers. Go to the ground floor and check all the breakers in the loading dock area.
3. If that didnt work, fuses might be blown or worse, and the technicians will have to fix it.

You can't find any of your objects, well-known bright stars, globular clusters nor even the Moon.

The telescope pointing calibration is bad.

1. If you used the 1996 Astronomical Almanac Bright Stars section to calibrate your pointing, go back and do it again using a *different* year's edition of the Astronomical Almanac. The 1996 Almanac Bright Star coordinates are incorrect.
2. see section on Pointing

7  Acknowledgements

This document is an (updated) compendium of various user guides written over the years. Thanks go to the following people for their earlier guides, upon which much of this document is based.

Mike Bessell, Jayanne English, Albert Bosma, Garry Kitley and Helmut Jerjen.

Version Information
V1.1: 990404, Kim Sebo: Updated and rearranged for inclusion on the WWW,
including notes from Helmut Jerjen, and autoguider info from
Mike Bessell.
V1.0: 970922, Mike Bessell: original version based on the combined notes
of Jayanne English, Albert Bosma, Garry Kitley and others.