revised 10/08/00

The MUSICOS instrument is a fiberfed echelle spectrograph, used on the INT. Fibers are attached under the IDS slit and led through the polar axis to the spectrograph, located in the temperature controlled room next to the observing floor


Start up TCS and UltraDAS the usual way: The observing system windows popping up will be exactly the same as if you were using IDS; No information what-so-ever will inform you that MUSICOS is in use. The TCS configuration will also be that of IDS, i.e. station cass, instrument IDS, agselect cass

The Cass TV will be looking at a dekker hole, typically of diameter 5", under which the fiberhead will be located.


Filling Cryostat:
Take extreme care when filling the cryostat as it is poorly mounted on the MUSICOS bench. If you accidently move it, chances are that you will need to align the CCD again. A procedure you do NOT want to do!

Rotator position:
The rotator position should under no circumstances be moved during the night. First, it serves no purpose as the circular fiberhead transmits no spatial information. Second, the fibers could be wrapped up as the rotator goes around and in worst case break! So: Do not move the rotator !, leave it at a fixed position, typically rot sky 0

Telescope Focus:
Focussing the telescope is a bit trickier than you might think. This is because the TV is focussed on the fiberhead, while MUSICOS aqcuisition is done on the dekker plates. Because of the distance between the dekker and the fiberhead (yet an unknown distance) the TV is actually out of focus. You can do the first rough focussing on the TV, but to find the real focus a set of focus images have to be taken. The throughput at the detector will then determine what focus position is best. Only with good seeing you can actually see the difference. As the focus offset should be a fixed value, we should be able to determine the focus offset once and for all.
10/08/00: Telescope focus on fiber: 14.65mm

Autoguider Focus:
As the telescope is focussed on the fiberhead, and the fiber is sitting below the slit, the autoguider focus needs to be adjusted. This has to be done manually on the first MUSICOS night, normally with the aid of the dutytech. The procedure is as follows:

Calibration procedure:
Proceed as normal with a 1/7 star calibrate


No special cautions to take. Proceed as usual: Center object on dekker, GSS to find guidestar, close guideloop.

Aligning CCD
The quick and dirty way:
The gold colored plate on which the cryostat is mounted can be moved using three screws; Two in front and one in back. Adjusting these screws allows you to Only apply small adjustments at a time, as the mount suffers from certain amount of hysterisis