MDM Observatory 2.4m Telescope Observing Report for 2026 Jan 05

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

Instrument: OSMOS

Worked for 12 hours (all night)
Conditions were Non-Photometric most of the night.
No equipment or software problems were encountered.

Seeing and Weather:
   Beg: Seeing 1.5 arcsec, Cirrus, Winds Calm
   Mid: Seeing 1.2 arcsec, Cirrus, Winds Calm
   End: Seeing 1.2 arcsec, Cirrus, Winds Calm

Observing Summary:

Cirrus of varying thickness all night - but never lost a guide
star.  Managed to get a lot done. 

In the second half the humidity was sometimes problematic. The 
weather station numbers on Jonathan Kemp's widget jump by 
5 points or so - there's something wrong with it.  I discovered
in the morning that water had been dripping off the roof on to
the loading dock, which was rather alarming, but Kitt Peak's 
numbers were something like 20 per cent lower and they never
did close. It's strange that only a few hundred feet would 
make such a difference - it was almost calm, which may have 
kept things from mixing much. 

There definitely were humid intervals -- I had to clear the 
dewar with dry nitrogen at least once. 

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Submitted on 2026 Jan 6 [7:07:47]