MDM Observatory 2.4m Telescope Observer's Report for 2004 Feb 20

Observer(s): Aeree Chung
Institution(s): Columbia University

Instrument: Nellie

Worked for 10 hours (all night)
Conditions were Mixed most of the night.
Problems were encountered, see the separate trouble report for details.

Seeing and Weather:
   High Humidity all night.
   Beg: Seeing 1.3 arcsec, Patchy Clouds, Winds Light & Variable
   Mid: Seeing 1.6 arcsec, Patchy Clouds, Winds Moderate
   End: Seeing 1.8 arcsec, Fog/Low Clouds, Winds Light & Variable

Observing Summary:

Cloudy during the day but got clear late in the evening. Dome was 
opened at 3:40 UT (RH=66%). Around 6 UT, the CCD became warm even
though the dewer was filled before observing. The pressure of the
tank was low but not sure if it was the cause. It was refilled and
the observation was resumed around 2 hrs later, after the CCD temp
got as low as the set temp. Also, the power went down for a second
around 7 UT. TCS had to be restarted. At 9 UT, RH went up to 83 % 
and the telescope was shut. An hour later, the RH got lower and the
dome was reopened at 13:30 UT. In spite of various troubles and the
high humidity, almost half of the targeted sources (9 galaxies in 
UMa cluster) were imaged (in R and H-alpha) last night.

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Submitted on 2004 Feb 21 [7:35:25]