Date: Sat, 27 Jun 1998 05:22:27 -0600
From: long@apo.nmsu.edu (Dan Long)
Subject: 2.5m night report 980626
                           FRIDAY JUNE 26, 1998
                     APACHE POINT OBSERVATORY SDSS 2.5m
                              OBSERVING  LOG
   The enclosure was opened and rolled off at 19:00.  The early roll-off
was done so the telescope could be slewed to zenith and the final portion
of the bulb seal around the primary mirror could be slit to relieve
pressure on the mirror.
   After a brief problem with azimuth motion due to one of the
interpolators being unconnected, we set up on the equator two hours west.
    Desired        Actual
   133:09:36      133:09:37
    46:42:06       46:42:09
    52:10:21       52:10:19
  The rotator needed to move about seven arcminutes negative from the above
position to properly align columns.
   At around 22:30 an adjustment was made to fill in the stripe from the
previous night's data.  It was later determined that the  offset didn't get
us quite where we needed to go to fill in the gap.  It was off by about 4
arcminutes when the overlap only allows about 2 arcminutes of error.  The
error was due to confusion on the starting point of the offset.
   133:04:24    Is where we ended up pointing
    46:47:47
    51:58:58
  It should be noted that the encoders stayed within an arcsecond or two of
the same value when parked, even after a few hours.  This is a dramatic
improvement over previous night's behavior.  The grounding work done today
on the encoders has helped a great deal.
  At about 1:45 a focus sweep was done in the 2 hrs west position.  Best
focus was around 1035, as it had been most of the night, and seeing was
around 1.1 arcseconds.
   At about 2:30 we slewed to 2 hours east to catch the HST field.
Unfortunately like last night the seeing in this direction was not as good.
The best we could manage was 1.5 arcseconds, and it was typically closer
to 1.8.  Once we were convinced that we couldn't get any better images, we
went back to 2 hours west.  The seeing had apparently degraded all around,
as we were only getting 1.4 arcseconds fwhm, even back in the west.
   Telescope was closed up at 05:00.  The west door made a couple loud pops
right at the end of the close cycle when it finished being drawn in.
Nothing looked wrong, but will keep an ear out for it happening again.
Final park values for the axes were
        300:04:08.4
         19:52:51.9
         90:29:55.0
                                Dan