MDM Observatory 2.4m Telescope Observing Report for 2023 Nov 19

Observer(s): Rachael Roettenbacher & Krisztian Vida
Institution(s): Michigan & Konkoly Observatory

Instrument: OSMOS

Worked for 5 hours (last half of the night)
Conditions were Mixed most of the night.
Problems were encountered, see the separate trouble report for details.

Seeing and Weather:
   High Humidity from 1800 until 0100.
   Beg: Seeing 1 arcsec, Clear, Winds High
   Mid: Seeing 3 arcsec, Clear, Winds High
   End: Clear, Winds Moderate

Observing Summary:

At the beginning of the night we refilled the dewar, 
and noticed that it is taking unusually long. 
The instrument temperature had increased to 7C, 
even though we refilled in the morning (the nut was 
tightened, and there was a steady dripping of LN2). 
The temperature got to nominal value in roughly 
two hours.  Eric was alerted.  
On test images with the Ne lamp, structures consistent with condensation
on the window to the detector could be seen.
 
Following phone instructions from Eric, we opened the valve 
on the top of the nitrogen gas tank on the southern side of 
the dome (one turn counterclockwise), opened the valve on the 
west side of the dome (quarter turn counterclockwise) 
to get a weak, steady gas flow, and connected the black 
tube with the gas flowing to the valve at the bottom 
of the telescope. With 1sec exposures with the Ne lamp 
on, the condensation seemed fading.  After about 40 minutes,
the condensation was gone.

At 22:50 humidity went up again and stayed high until 01:00.
Instrument temperature remained stable through the night, 
and there were no visible signs of humidity building up in 
the instrument.

Please check the spectral flat lamp, it doesn't appear to 
turn on when using the MIS gui (says it's on, but no light 
in the images).  

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Submitted on 2023 Nov 20 [6:51:19]