MDM Observatory 1.3m Telescope Observing Report for 2011 Aug 28

Observer(s): Jules Halpern
Institution(s): Columbia

Instrument: R4k

Worked for 10 hours (all night)
Conditions were Non-Photometric most of the night.
No equipment or software problems were encountered.

Seeing and Weather:
   Beg: Seeing 1.3 arcsec, Cirrus, Winds Light & Variable
   Mid: Seeing 1.1 arcsec, Clear, Winds Light & Variable
   End: Seeing 1.3 arcsec, Clear, Winds Light & Variable

Observing Summary:

This was my last night on the 1.3m, and finally a clear one,
except for a strange, low haze.

I pointed at many targets, with no problems tracking and
guiding.  At most 6 images out of 170 had some guiding
problem, but I think that some of those can be attributed
to a cosmic ray hitting near the guide star, which quickly
recovered.  Guiding in declination started out a bit less 
stable than in RA, but it was possible to fiddle with the 
parameters to get acceptable behavior.  After that, round 
images with seeing of 1.1-1.3 arcseconds could be achieved
in 5 minute exposures.

There was one case of a diagonal telescope jump in a guided
exposure, but that is an old story, and probably due to some
kind of mirror flop.

Primary mirror could use a wash.

I won't comment much on the R4k, since it was pressed into
service before it was really ready.  It's difficult to
get sky flats using the 1Kx1K setup because the edges 
saturate and roll off at relatively low count rates.

Thanks to the technical staff who worked so hard to get
the telescope ready for observing this season.


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Submitted on 2011 Aug 29 [6:22:39]