MDM Observatory 2.4m Telescope Observing Report for 2025 Jun 29

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

Instrument: OSMOS

Worked for 8 hours (all night)
Conditions were Mixed most of the night.
No equipment or software problems were encountered.

Seeing and Weather:
   Clouds from 1:20 until 3:00.
   Beg: Seeing 1+ arcsec, Clear, Winds Moderate
   Mid: Seeing 1+ arcsec, Clear, Winds Light & Variable
   End: Seeing 1+ arcsec, Patchy Clouds, Winds Calm

Observing Summary:

Generally a fine night; not a problem as such but pointing seems
to be sometimes off in RA, by 10 seconds of time or more in some
cases.  I have not established whether this is an error in the 
model or random.  I had to reset on bright stars in the field
center a few times -- it's a bit of a rigarmarole but goes very 
quickly with practice, so I lost very little time.

Around 1:20 AM, a patch of broken, but opaque high cloud rolled 
over coming from the southeast.  This hung around for over an
hour, but I managed to get some targets in the gaps, and then it
completely dissipated before twilight.  I could see it on the 
longwave IR GOES animation on the College of DuPage site. 


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Submitted on 2025 Jun 30 [5:43:57]