MDM Observatory 2.4m Telescope Observer's Report for 2007 Jun 30

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

Instrument: Modspec + echelle CCD

Worked for 9 hours (all night)
Conditions were Non-Photometric most of the night.
Problems were encountered, see the separate trouble report for details.

Seeing and Weather:
   Beg: Seeing 1+ arcsec, Clear, Winds Moderate
   Mid: Seeing 0.9 arcsec, Cirrus, Winds Calm
   End: Seeing 0.9 arcsec, Cirrus, Winds Moderate

Observing Summary:

Generally clear, but with episodes of very thin cirrus blowing 
through from the north; with the moon just past full this was
very noticeable.  Seeing generally good.  Winds died down
early and picked up again late.  No monsoon activity visible,
even far to the east.

I used the retrocam to look for an eclipse in one of my objects
(didn't find it, unfortunately).  It worked well, but there's a
sizeable area in the upper right quadrant (as viewed with the
default ds9 params) which appears to have some kind of crud on
it, possibly ice from the looks of it.  This didn't affect my
differential photometry.  Interested parties may examine
affected images on agung at /lhome/obs24m/thor/jun07/retrocam.

It may be of interest that, when one has been guiding on the 
slit jaws with modspec and goes to direct guiding for retrocam,
the guider does not need to be refocused.  The +128 unit change
in telescope focus pretty much compensates for the difference
in focus between the guider and the instrument.  

------------------------------

Submitted on 2007 Jul 1 [5:06:35]