MDM Trouble Report for 2014 Sep 21

Telescope: 1.3m
Observer(s): Halpern (Columbia)
Instrument: Templeton

Problem(s) Encountered:
No action is required, but I am filing this report about a couple
of peculiar behaviors of the 1.3m for archival purposes, in case
anyone else encounters them.  About once a night I have seen the 
following:

1) What we refer to as the `flop' of (probably) the guide probe
mirror, which causes a diagonal jump of the image by about 10
arcseconds.  This is a legacy feature of the MIS.

2) An image which is elongated or doubled in the E-W direction
by about 2 arcseconds.  The last time I saw this was in August
2011, when it was traced to a 1.8 Hz oscillation, probably a
natural oscillation of the telescope that was amplified by
the servo motor, according to Richard Treffers.  It was fixed,
and this is the first time I have seen it again in the past
three years.  I am mentioning this because, being in RA,
it is not the same phenomenon as the N-S nodding.  It is
easy to mistake this for poor focus, but it is not a focus
problem and won't be fixed by changing the focus. It is a
fast oscillation that can't be resolved even in a 1 s exposure




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Submitted on 2014 Sep 22 [15:07:56]