Changes

SPUPNIC

22 bytes added, 22:09, 21 August 2016
/* Dome Flats */
====Dome Flats====
* Go behind the control room desk and check that the black rheostat is dialed down to zero * Flip the switch next to it to On * Dial the rheostat up to 220 V (do not exceed that value as you will blow the lamps) * The lamps on the top end of the telescope should now be on * Open the mirror cover * With the telescope vertical, rotate the dome to 127 degrees, so that the white flat-field screen is just to the east of the south pier * Set the telescope RA to HA = 0 * Slew the telescope in Dec to the south pole (-90 degrees), while keeping an eye on the spectrograph cables * The cables will look like snagging, but they will not if you are at HA ~ 0 * Slew Through the pole, to -86.5 degrees (on the other side of -90) * Try not to overshoot as the pointing limit is at -85 on that side * If you run into the limit, an alarm will sound and the telescope will stop moving * To recover: turn the over-ride key next to the console while backing the telescope out towards the north in Dec * With the telescope at HA ~ 0/12 & Dec ~ -86:30, the telescope should be quite well centred on the flat-field screen * In the control room, take some trial exposures to check the count level, aim for ~40k counts * The lamps are quite red, so blue settings (e.g. G4) struggle for counts * In that case, it is fine to crank the slit wide open to let more light in (you do not care about resolution here) * Take as many flats as you like (say, 11?) once you have established an appropriate exposure time * When you have the flats, slew the telescope back to the zenith (again keeping an eye on the cables) * Dial the rheostat down to zero * Flip the switch to Off * Close the mirror cover
====Focusing The Spectrograph - running a Hartmann sequence====
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