MDM Observatory 2.4m Telescope Observing Report for 2014 Jan 25

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

Instrument: modspec + echelle CCD

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:
   Clouds from start until 9 PM.
   Beg: Seeing 1+ arcsec, Patchy Clouds, Winds Light & Variable
   Mid: Seeing 1+ arcsec, Clear, Winds Light & Variable
   End: Seeing 1+ arcsec, Clear, Winds Calm

Observing Summary:

Humidity was a little dicey for much of first half but settled
out.  There was a raft of lowish clouds overhead at sunset, but
clear sky to west and the clouds weren't around for very long.  

During the day the primary was running below the dew point, so
I set the mirror A/C to actually heat the mirror.  This worked
very well -- later on it was good to have the mirror a little
on the warm side for extra reassurance in the humidity.  And even
though the mirror was a degree C or so above ambient, the 
seeing was satisfactory all night.

Big trouble, though, in that modspec shutter stopped working - 
see report.  Also, weather station isn't reading, I think -- 
humidity is unrealistically low and wind once again pinned
at zero.  Also, one of the airbag valves is chattering continuously
and the hard-point loads are not quite right.  And the 
dropout looked badly skewed on closing.  If it rains, it 
pours ... ! 

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

Submitted on 2014 Jan 26 [6:52:32]