MDM Observatory 2.4m Telescope Observing Report for 2011 Sep 14

Observer(s): John Thorstensen
Institution(s): Dartmouth

Instrument: OSMOS + 'blue' 4k

Worked for 9 hours (all night)
Conditions were Mixed most of the night.
No equipment or software problems were encountered.

Seeing and Weather:
   Clouds from start until 10 PM.
   Beg: Seeing 1+ arcsec, Patchy Clouds, Winds Moderate
   Mid: Seeing 1+ arcsec, Clear, Winds Light & Variable
   End: Seeing 1+ arcsec, Clear, Winds Light & Variable

Observing Summary:


Thunderstorms around 5 PM, but it cleared off very quickly
around sunset, with some clouds lurking for a little while.

This isn't 'trouble', but the 4k on OSMOS started developing
fog in the middle of the dewar window around midnight, with the
RH well below the limit.  This slowly grew through the night,
wiping out the middle of the spectral range; since I was 
working with the 4x1k readout and inner slit, the H-alpha
region was clear, so I kept going.  Closed a tad early because
standards would have been pointless. 

A port for dry LN2 flush would be a real help under these
conditions.

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Submitted on 2011 Sep 15 [5:39:55]