Date: Sat, 10 Oct 2009 12:36:51 -0000 (UTC)
Subject: 3.5m Night Log 20091009
From: "Gabrelle Saurage"
                       Apache Point Observatory
                       3.5m Telescope Night Log
                       Friday, October 9th, 2009
                                                        ACTUAL
 ASTRONOMER      OBSERVER(S)            INSTRUMENT     START  FINISH
 ------------------------------------------------------------------
 A.Kowalski      A.Kowalski             DIS            19:15  07:00
  INST       SCHEDULED      WEATH     EQUIP      OBS     NOT USED
 I/ROW/DN   START  FINISH   D    B    D    B    D    B    D    B
 -------------------------------------------------------------------
 UW02/O     18:46  06:55    0    0    0   0.6  3.9  7.7   0    0
 note: scheduled times listed include instrument change time
        ------------- ACTIVITY LOG --------------
 Observing Specialist: G.Saurage
Began the night with clear skies and sub-arc seeing. Conditions had only one way to
go. Luckily we only had thin clouds on and off and moderate seeing.
UT 08:44 while happily tracking on a field for quite some time the alt drive
spontaneously reported "Motor control buffer empty" as stars streaked across the
guider. There was no alarm sound or error message. A few blue warnings passed by
silently before the guiding failed.
I tried the various levels of bringing the alt axis back. Ultimately it needed to be
reset and during this process it lost it's position, thinking it was at 0 the min
limit but it was actually at 41 degrees. I set.position and then did large slews
once the axis was back up. Checked pointing and all was well. Lost about 30 minutes.
UT 10:05 Alt "Servo error too large" error. Stop and init recovered. Lost 180 sec
exposure. Then while tracking stars would elongate for a guider frame then
stabilize. This happened 3-4 times and corresponded to a blip on the az-alt-error
strip chart.
UT 10:51 Az Servo error too large" error.
                     ------- FAILURE LOG -------
 PROG   INST   FAILURE MODE     TIME
      (SEDFNVOG)   TI/SHU    START  FINISH  DESCRIPTION
 -------------------------------------------------------------------
 UW02    D          T/S      02:44  03:18   Alt motor control buffer empty
              ---------------- FOCUS LOG ---------------
 Time  Instrument  Focus     Az  El  Temp Strc Prim  Sec  Air  filt  FWHM
 ------------------------------------------------------------------------
 19:12 dis-slit   112( 161) 131  78   7.3  9.2  7.9  8.1  8.1     0.89
 21:36 dis-slit    64( -16) 140  74   6.6  6.6  6.5  5.5  6.2     1.79
 23:06 dis-slit   146(  58)   1  52   6.9  6.1  6.5  5.1  6.1     1.16
              ------------- WEATHER LOG ----------------
                                  Wind                      Precip.or
    Time   Temp F Dewp F  MPH  Direction    Dust    Sky    Conditions
   -------------------------------------------------------------------
     16:00    50    17      6     2    (N)    979    clear     none
     17:00    48    18     11   322   (NW)    998    clear     none
     18:00    47    17      7   305   (NW)    943    clear     none
     19:00    45    16      7   285  (WNW)    926    clear     none
     20:00    46    15      8   267    (W)    869    clear     none
     21:00    45    16      5   256  (WSW)    945    clear     none
     22:00    45    17      8   224   (SW)   1078    clear     none
     23:00    44    18      8   228   (SW)   1448    clear     none
     00:00    45    17      6   204  (SSW)   1395  ptly cldy   none
     01:00    43    17      9   191    (S)   1844 mstly clr    none
     02:00    43    16      6   183    (S)   1408 mstly clr    none
     03:00    44    16      6   201  (SSW)   1399  ptly cldy   none
     04:00    43    15      6   191    (S)   1340  ptly cldy   none
     05:00    41    16      5   162  (SSE)   1501  ptly cldy   none
     06:00    43    15      8   185    (S)   1379 mstly cldy   none
                             TELESCOPE STATUS
     Telescope drives operational. Current TCC version: 2.10.0
     Current TUI version:  TUI 1.6.2