MDM Trouble Report for 2024 Jul 01

Telescope: 2.4m
Observer(s): Terndrup et al. (OSU)
Instrument: OSMOS

Problem(s) Encountered:
After focussing the telescope, we found that our images were
often elongated in the E/W direction, or had a regular-looking
core but an extended tail pointing to the east.  We consulted
with Eric about the operation of the guider, and together we
noted that the X tracking correction had a much larger scatter
than in Y.  The orientation of the guider images is E to the
left and N to the top.

We than ran experiments in which we took a series of continuous images on
the guider, with guiding off, to see how the telescope was
tracking. At semiregular regular intervals (roughly 12 sec), the image
would take a hop of 3-5 arcseconds towards the east (i.e.,
the telescope was taking small jumps to the west).  It did not
happen every time, but often enough that any image longer than
30 seconds had a good chance of being affected by this, since
the guider could not compensate for the hopping instantly.

We let the telescope track without guiding, and noted that
the telescope right ascension showed the telescope
drifting west.  Over about a half hour, these little hops 
accumulated to about 110 arcseconds.  

Under these conditions, we could not do our main program of
narrow-band slitless spectroscopy.

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Submitted on 2024 Jul 2 [1:25:06]