MDM Observatory 2.4m Telescope Observing Report for 2011 Apr 23

Observer(s): Hamann, Shields
Institution(s): UF, OU

Instrument: OSMOS

Worked for 6.0 hours (all night)
Conditions were Non-Photometric most of the night.
Problems were encountered, see the separate trouble report for details.

Seeing and Weather:
   Beg: Seeing 1.2 arcsec, Cirrus, Winds Light & Variable
   Mid: Seeing 1.2 arcsec, Cirrus, Winds Light & Variable
   End: Seeing 1.0 arcsec, Clear, Winds Light & Variable

Observing Summary:

The mirror temperature started to rise abruptly around mid-day Apr 23 (local), 
increasing from 10.2 to 14.5 degrees in 4 hours. The mirror temp remained 
higher than ambient throughout the night. The temperature difference was 
largest at morning twilight, when the mirror temp was ~11.5 compared to ~9.0 
for ambient. 

What can I do about this? 

The conditions were overall good and there were no other failures. We lost about 
an hour mucking about with target and guide star acquisitions: We needed to 
determine guider offsets experimentally after a slit rotation, and we initially used 
the wrong procedures after changing from the 1.2 center to 1.2 inner slits.

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Submitted on 2011 Apr 24 [5:32:03]