MDM Trouble Report for 2009 Aug 25

Telescope: 2.4m
Observer(s): John Thorstensen (Dartmouth)
Instrument: modspec + echelle CCD

Problem(s) Encountered:
The first exposure of the night, a 900-sec science exposure, was
very weak.  The star appeared healthy on the slit jaws, and the
light path was otherwise clear, so the only explanation I can
think of is that the shutter only opened partially.  When I saw
this I tested the shutter by opening and closing it repeatedly
and taking a comp exposure and a brighter star, and these both
looked perfectly normal.  The shutter never malfunctioned for
the rest of the night, so I am sure it is useless to try to 
reproduce this.  But it might be good to be sure that a spare
is available.  If worse comes to worst, I can work without 
a shutter as long as I don't take any short exposures.

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Submitted on 2009 Aug 26 [6:06:21]