MDM Observatory 1.3m Telescope Observer's Report for 2007 Dec 12

Observer(s): armstrong
Institution(s): columbia

Instrument: 4K

Worked for 8.5 hours (most of the night)
Conditions were Photometric most of the night.
No equipment or software problems were encountered.

Seeing and Weather:
   High Humidity from dusk until 22:00.
   Beg: Clear, Winds Calm
   Mid: Seeing 1.5 arcsec, Clear, Winds Calm
   End: Seeing 1.2 arcsec, Clear, Winds Calm

Observing Summary:

High humidity kept us closed until about 22:00.  Jason Eastman wanted 
to be conservative about opening, as the instrument is sensitive to 
humidity.  So we waited until it had dropped to 75%.  Observed for about
40 minutes before we noticed condensation on the mirror.

Flushed mirror with exhaust from the n2 tank, for about an hour. 
Condensation went away.  Kept observing under a clear sky for the
rest of the night.

------------------------------

Submitted on 2007 Dec 13 [5:37:55]