From: Russet McMillan
Subject: 3.5m Night Log 20000211
Date: Sat, 12 Feb 2000 06:30:36 -0700 (MST)
                          FRIDAY FEBRUARY 11, 2000
                         APACHE POINT OBSERVATORY
                              OBSERVING  LOG
                                                          ACTUAL
ASTRONOMER      OBSERVER(S)        INSTRUMENT   DATE   START FINISH
York		Crotty             DIS          2/11   18:10 18:30
Brown           Brown    	   Echelle      2/11   18:39 00:08
Strauss		Strauss, Fan	   DIS          2/12   00:12 05:55
 INST        SCHEDULED     WEATH     EQUIP      OBS    DAY   NOTUSED
I/RS/DN    START FINISH   D    B    D    B    D    B   USE   D    B
UC11/R     17:39 18:39    -    -    -    -    -    -   1.0   -    -
WS01/R	   18:39 00:10    0    0    0    0   0.2  5.3   0    0    0
PU01/R     00:10 05:55    0    -    0    -   5.8   -    0    0    -
(note: times listed include instrument change time)
                              ACTIVITY LOG
(* means a trouble report has been issued or appended to)
Observing specialist: McMillan
The weather was very nice for the entire night, with clear skies, good
to moderate seeing, and mid-strength winds.  The NA2 guider was
re-installed late this afternoon, causing a slight delay in opening
the telescope for cooling and using up some of Adler's time.
Preliminary tests of the guider showed reasonable images.  When Adler
did get going, they tried using DIS in imaging mode, but the mirrors
hadn't homed correctly, and they were unable to get anything useful.
The echelle behaved well during first half, with the instrument
correctly completing an exposure even when a temporary loss of
connection caused trouble for both the slitviewer and the remote
Remark.  It's worth noting that the instrument control computer is
quite robust at times like these and has saved many long exposures in
the past.  We did have some tracking trouble when a target got close
to the zenith, but tracking was generally good at more reasonable
altitudes, and pointing was excellent.  Some examples of sudden motion
were seen, as detailed in the comments below.
During second half, the guider was in use and worked exactly as it
should, which was a great relief for an observing specialist tired of
babysitting DIS.  No streaking or contamination was evident in the
images.  The guider was getting approximately 1.1 arcsecond seeing --
similar to what we found for the slitviewer during focus, and often
better than DIMM's measurements.  Incidents of image motion were
extremely obvious on the guider monitor both in the FWHM and offset
size; I recommend that anyone looking for good timestamps on such
events check the GSDataPix values in the TCC logs.  We were seeing 2-4
examples of motion per hour, generally not associated with slews
(slews were 1/2 to 1 hour apart).  With a sufficient bright guide star
and short exposure times, the motions had little or no effect on the
data-taking.
                            OBSERVER COMMENTS
J. Brown (WS01):
It was a very nice and productive night overall with perhaps
the best conditions I've had in my ~1 year experience with
APO.
There was a communications link loss that confused us (the
remote people) but with the AO's help things were restored
in about 10 minutes without loss of integration time.
Several comments about tracking.
We were observing an object at +30 32 00 (2000), which passes
near the zenith, starting about an hour east of the meridian.
There was an overwhelming tendency for guiding corrections to
go in the same direction, the star needing to be pulled back
from its drift up and to the right in the slit viewer window.
Tracking became intolerably poor at an hour angle of about 10
minutes east, at which time we went to another object, returning
to +30 32 00 about half an hour later.
Once we were west of meridian I began seeing the tracking
jumps which Russet said had been frequently noted before:
the telescope would "suddenly" move about 1.5 to 2 arcseconds
(move well off the echelle slit, though the dark slit was
still discernable in the wing of the star) to the right as
seen in the echelle slit viewer window, and about a minute
later would "suddenly" move most of the way back.  "Suddenly"
here means short compared to the 37-second guide frame cycle
we were using.  These jump events happened roughly ten to twenty
minutes apart; between them the tracking was good, and the
systematic guiding trend I noted before meridian passage was
no longer present.  I do not now remember any jumps while
east of the meridian, but am not absolutely certain there
were none.
M. Strauss (PU01):
Absolutely no problems to report.  The telescope worked perfectly, and
the weather was great.  We got 6 high-redshift quasar candidates, and
worked at high efficiency all night, thanks to Russet's usual
efficient and expert help.
                                FOCUS LOG
                             FEBRUARY 11 2000
                                                 Wind
Time   Inst        Focus     Az  El   #Temp    Dir  MPH  filt  FWHM "
18:45  Echelle   166(   )    95  76  2.1/3.4   260   11  clear 1.11
21:00  Echelle   191(-538)  265  77  1.9/1.6   264    9  clear  1 micron per 0.1 cu. ft.
                             TELESCOPE STATUS
Primary, secondary, and tertiary mirrors in place and collimated.
Primary support system operational.  Mirror ventilation system in
place.  Telescope drives operational.  Current Remark version: 2.55b5.
Current guide software version: GIm Ctrlv3.0b27.  Current TCC version
is 2.2.2.
- Russet McMillan