MDM Trouble Report for 2007 May 31

Telescope: 2.4m
Observer(s): Sivakoff (The Ohio State University)
Instrument: Echelle

Problem(s) Encountered:
On-zenith pointing is accurate; however off-zenith pointing
appears 30 -60  off:
Throughout the early portion of the night I noticed my targets
were ~20-40  off from where I expected them to be; however,
this did not impact the H alpha imaging project. In addition to
noticing this in my images, I would try to find the nearby
bright stars near my targets using the guide camera at the
center. For example, a star expected at 11 46 3 47 46 46 was
found at 11 46 5.5 47 47 44, approximately 60  off at UT~07:34.
For mosaic imaging of galaxy clusters, I tried to fix this
problem. I completely reset the pointing, checking several
bright stars near zenith. Typically only minor adjustments
were needed to set the RA/DEC encoders. Again, I tried a bright
star off zenith and found a ~30  offset. (Star expected at
15 30 55.7 +64 12 31.0 was at guide center when RA/DEC =  
15 30 54.8 64 13 6 at UT~09:15). This problem is unresolved.
Impact: 1.5 Hours

MIS Filter-wheel appeared to freeze during a planned R-band
observation with xmis unresponsive for a small period:
After the preceding problem, I switched to the R-band filter
for Cluster imaging. With a test image (junk.202.fits), I
noticed a bright side of the chip. Looking at the xmis window,
I noticed that there was never a done issued for the
filter-wheel change. xmis would not respond to any changes.
After quitting out of xmis, I tried to restart xmis several
times. It did not succeed to restart until nearly 0.5 hours
passed. When it did restart I took three test images, one in I
band folled by 1 in my H alpha filters. No strips were seen
and the expected flux drop between the two was seen. I took a
third test image in R and found no problems. This problem
appeared to solve itself.
Impact: 1 Hour

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Submitted on 2007 May 31 [4:36:15]