MDM Trouble Report for 2017 Aug 18

Telescope: 1.3m
Observer(s): Bord, Clarkson, Aufdemberge, Vowell (UM-Dearborn)
Instrument: ANDOR

Problem(s) Encountered:
See also: https://docs.google.com/presentation/d/1rMtvuE3E1kW_KtNPi3PWRbrNLvmX_y9k1XMpZLMiz5c/edit#slide=id.p5

1. Apparent dust donuts move visibly during a sequence of 20 images, 
which was unexpected. 

2. Mysterious large obscuring structure(s), partially in focus, that appears to 
move (at one point covering half the visible sky, this at 1x1 binning with the 
Andor), then vanishing. Visible in the science images. Later, an obscuration 
was seen again, this time with a more complicated structure. Finally, while 
attempting morning twilight flats, an obscuration was seen again, 
this time moving rapidly (about 1/3 the field of view per 10s exposure). 

Observers not sure what these structures are. Visual inspection turned up 
nothing obvious on the primary or secondary mirror, and nothing obviously
blocking the light path. Attempted closing and
re-opening the MIS hatch cover had no effect on the obscuration.

Our best guess is that this might be wildlife of some sort, possibly crawled
into the baffle in the middle of the primary mirror.


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Submitted on 2017 Aug 19 [5:42:29]