MDM Observatory 2.4m Telescope Observing Report for 2011 Apr 10

Observer(s): Stoll
Institution(s): OSU

Instrument: OSMOS

Worked for 7 hours (most of the night)
Conditions were Photometric most of the night.
Problems were encountered, see the separate trouble report for details.

Seeing and Weather:
   High Humidity from 19:00 until 20:30.
   Beg: Seeing 1.2 arcsec, Clear, Winds Moderate
   Mid: Seeing 3 arcsec, Clear, Winds Moderate
   End: Seeing 2 arcsec, Clear, Winds High

Observing Summary:

The time lost at the beginning of the night after the humidity 
fell was due to observer malfunction instead of equipment 
malfunction.  I had condensation on the dewar window after the 
last two days of >90% humidity.  I caution all OSMOS and 4k users 
to squelch the instinct to take daytime calibration frames when 
the humidity is high.  After consulting with Bob on the location 
of the dry nitrogen line, recovered relatively quickly.  No 
further problems.  Clear weather but truly terrible seeing 
for the second half of the night.

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Submitted on 2011 Apr 11 [7:16:28]