Date: Mon, 25 Aug 2003 05:04:30 -0600 (MDT)
From: Jack Dembicky
Subject: 3.5m Night Log 20030824
                         Apache Point Observatory
                         3.5m Telescope Night Log
                         Sunday, August 24, 2003
                                                          ACTUAL
 ASTRONOMER     OBSERVER(S)             INSTRUMENT     START FINISH
 --------------------------------------------------------------------
 B.Gillespie    J.Dembicky, R.McMillan  SPIcam         20:15 22:25
                J.Barentine, J.Davis
                                        GrIm           22:25 00:00
                                        Echelle        03:40 05:10
  INST        SCHEDULED      WEATH     EQUIP     OBS     DAY  NOTUSED
 I/RO/DN     START FINISH   D    B    D    B    D    B   USE   D    B
 --------------------------------------------------------------------
 EN01/O      20:33  05:37  3.7   0    0    0   3.9  1.4   0    0    0
 note: scheduled times listed include instrument change time
                ------------- ACTIVITY LOG --------------
 Observing Specialist: J.Dembicky
 Russet, John B, and Myself rotated the tertiary to the NA2 port.
 Next, Russet and Jon D. collimated the primary mirror of the telescope
 using SPIcam.
 Next Russet focused SPIcam to do a pointing check.  After several stars
 she determined that the pointing was good enough and decided to not do
 another Echelle pointing model.
 John mounted GrIm at around 22:25 so we could get an instrument block.
 After the pointing block was finished (actually they did 2 of them for
 GrIm) the clouds rolled in and stopped observations until around 03:40.
 At 03:30 John, Russet, and I decided to go ahead and manually rotate the
 tertiary back over to the Echelle to check pointing, and do a pointing
 model if necessary, which Russet started and John and I finished.
Russets commentary on tonights activities is below:
We began the night by following the instructions Dave Woods gave us
yesterday for rotating the tertiary by hand.  This proved arduous but
successful, so the tertiary mirror was facing the NA2 port when we
opened.  Using SPIcam, we helped Jon Davis get the primary mirror
collimated.  Collimating the primary had the additional advantage of
improving pointing.
We next spent a while trying to judge (through clouds) whether the
pre-shutdown pointing model or the model taken last night worked
better.  We concluded that both were imperfect for the current
collimation, but about equally as good as each other, with stars
coming up within about 15 arcseconds of the boresight.  Last night's
model has been implemented as the default.
We were considering whether to take another pointing model next, but
the proper way to do a pointing model at the echelle begins by
rotating the tertiary while the telescope is tracking -- not possible
under the current conditions.  Without that crucial step, we weren't
sure that a new model would be a significant improvement.  So we went
on to the next NA2 project, which was instrument blocks with GRIM at
f5 and f20.  This took a while due to clouds passing by, but the
results looked quite good.  The f5 instrument block is now correct
for the first time in at least 5 years, and the new f20 instrument
block should improve pointing in that mode (assuming that we can get
a good pointing model as a starting point!).
After the GRIM work, the clouds grew thicker and more widespread, so
we weren't able to do more.  Despite the clouds and the east winds,
however, seeing was quite good tonight -- we got images of  1u per 0.1 cubic feet.
                               TELESCOPE STATUS
   Telescope drives operational. Current Remark version: 2.85b
   Current guide software version: guider? what guider?
   Current TCC version: 2.7.1  Current TUI version: TTUI