MDM Observatory 2.4m Telescope Observing Report for 2015 Oct 19

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

Instrument: Modspec + echelle CCD

Worked for 3 hours (off and on through the night)
Bad weather most of the night.
No equipment or software problems were encountered.

Seeing and Weather:
   High Humidity from 1 AM until end.
   Beg: Seeing 1+ arcsec, Patchy Clouds, Winds Moderate, closed 830-1100
   Mid: Seeing 1+ arcsec, Patchy Clouds, Winds Moderate
   End: Overcast, Winds Moderate, closed

Observing Summary:

Clouded up after a slow start, then it cleared fairly well after 
a couple of hours, but humidity spiked and fog rolled in after
midnight. I had to close quickly so left the instrument rotated.  

A couple of glitches not rising to the level of a trouble report.

First, at the start the pointing was far enough off that I didn't
see a bright star right away.  I re-zeroed pointing at the
zenith using the postit note coordinates, but I still wasn't
finding bright stars.  I then went to look for Vega, and found
it many arcmin off in RA.  I rezeroed the pointing on Vega,
verified that it was correct by finding another bright star,
then tweaked the pointing very close to the zenith, parked
the telescope at the zenith, and found that the tiltmeters 
disagreed badly with the postit note in RA:
Old postit note:  +0.04  -0.02
Correct zenith:   -0.15  -0.03
I wonder if someone zeroed the coordinates on the OSMOS 
inner slit or something.  Perhaps we should replace the 
postit note with a granite obelisk, or at least something less 
ephemeral.

Also, the instrument rotator didn't rotate on the first attempt.
Power cycling the rotator box fixed this.


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Submitted on 2015 Oct 20 [5:46:31]