Date: Thu, 27 May 1999 06:26:36 -0600
From: long@apo.nmsu.edu (Dan Long)
Subject: 2.5m obslog 990526 ( MJD 51325 )
                          WEDNESDAY MAY 26, 1999
                     APACHE POINT OBSERVATORY SDSS 2.5m
                              OBSERVING  LOG
    Observering team:   Dan Long                (APO)
                        Francisco Castander     (UC)
                        Adrian Pope             (CMU)
   We may have gotten our first extragalactic spectra tonight!  The weather
kept us closed until 02:30, but the last couple hours went very well.
   The telescope was opened tonight at around 19:15.  I managed to get the
nose cone off, the drive surfaces clean, and the fiducials set by about
20:00.  The sky was unsettled, so the plan to swap cartridges was put on
hold until the skies cleared a bit more.  The skies worsened, so I ended up
closing at around 20:30, and remained closed until 01:30.
   By this time it was too late to put on the coma plate, so we went with
the same field as last night, plate 135.
        Coords  248.692869, 0.023789  J2000
        Calibration offsets  -.004, .001, -.06
        Best focus  3375
   It was about 02:30 when we got set up on the field.  Guiding was started
around 03:15.  We took three 20 minute exposures of the field.  There were
spectra in them!  Some reduction will have to be done to tell if any of the
extragalactic objects managed to fight their way through the bright
moonlight, thin clouds, and high airmass.
   A note on the guiding performance.  With a little over half the stars in
the fibers, we turned on guiding and within a couple itterations the stars
were well centered in all fibers ( no scale correction was used, or
apparently needed ).  Guiding kept the stars very well centered for about
30 minutes.  They started to move more toward the edge in the next half
hour.  This could have been due to the high airmass causing differential
refraction different from what the plate was drilled for ( we were between
35 and 40 deg in the last half hour ).
   At about 04:45 we put the telescope in stow position, and took flats
with a quartz lamp pointed at the closed east door of the enclosure, but
with the enclosure still clear of the telescope.  Twelve second exposures
seemed about right.  The enclosure was closed at about 05:30.
   The spectrograph transfer dewar was filled tonight at about 18:45, and
was hungry again by 04:00.  Since I had the telescope down at the horizon
less than an hour later, quite a bit of nitrogen was undoubtedly lost.  The
transfer dewar was topped off after the telescope was put away for the
night.
                                WEATHER
   Weather tonight started partly cloudy.  It became mostly cloudy around
20:30, and remained so until about 01:30.  It was mostly clear after that.
Winds were light westerly, with low dust and humidity.  Temperatures were
in the low 50s all night.
                                  Dan