MDM Observatory 2.4m Telescope Observing Report for 2013 Feb 15

Observer(s): Hainline, Chen
Institution(s): Dartmouth College

Instrument: OSMOS

Worked for 11 hours (most of the night)
Conditions were Non-Photometric most of the night.
No equipment or software problems were encountered.

Seeing and Weather:
   High Winds all night.
   Beg: Seeing 1.5 arcsec, Patchy Clouds, Winds Moderate
   Mid: Seeing 2.5 arcsec, Cirrus, Winds High
   End: Seeing 3.0 arcsec, Clear, Winds Above Limit

Observing Summary:

Tonight's sky at sunset was full of clouds, and while they were unfortunate early on,
they cleared and made the way for very heavy winds. This meant that the seeing 
varied between 1.5 arcseconds for a very short while near the beginning of the 
night to 3+ arcseconds near the end. 

We started with some successful long slit observations, and then moved to the MOS
portion of our observing run. Here, we were quite pleased to be able to line up
the slit masks easily, and we took science data for two different MOS fields.
MOS slit aligning and data taking takes 3 hours per target, and after two sets, 
we attempted to go to SN2012a, but the seeing at this point was 3 , which was 
not even close to the minimum seeing requested. 

After this, we returned to a third cluster, but found that the person who sent in
the slit masks did not send an updated version in, and as such, the slit mask would
not have the correct plate scale. It was while we were examining this that the
wind reached 40 mph (around 5:00 AM). At this point, there was not enough time
to start in on any other projects, and since we had already closed down the
telescope we decided against taking morning twiflats flats (although the wind did 
not seem to be dying down).

Early in the evening, we set the RA tracking rate to 15.05 as suggested by John 
Thorstensen, which actually helped to change the delta y error on the guiding to 
be more centered around 0 rather then negative, solving a previous issue. I think 
that the wind was serving to make the tracking pretty rough throughout the 
night. Other than the wind, we had no telescope issues. The shadow we were 
reporting across our flat field images was just the guide probe, we were forgetting 
to put it at the origin when obtaining our flat fields. We were also able to swap 
out MOS slit masks pretty easily, and the ones we put in worked quite well. 

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Submitted on 2013 Feb 16 [5:46:43]