Subject: 3.5m Night Log 20251123
From: mcmillan@apo.nmsu.edu
Date: Mon, 24 Nov 2025 12:14:39 +0000 (UTC)
                      Apache Point Observatory
                      3.5m Telescope Night Log
                      Sunday, November 23, 2025
PROG  PI ASTRONOMER      OBSERVER(S)
--------------------------------------------------------------------
UW05  C.Chandler        C.Chandler
BY04  A.Mosenkov        A.Mosenkov
                         ON-SKY
PROG  INSTRUMENT     START   FINISH
--------------------------------------------------------------------
UW05  ARCTIC         --:--   --:--
BY04  KOSMOS         --:--   --:--
   PROG       SCHEDULED      WEATH     EQUIP     OBS     NOT USED
 I/ROW/DTN  START  FINISH   D    B    D    B    D    B    D    B
-----------------------------------------------------------------
UW05/R      17:07  00:10   4.5  2.5   0    0   0.0  0.0   0    0
BY04/R      00:10  06:33   6.4   0    0    0   0.0  0.0   0    0
note: scheduled times listed include instrument change time
              ------------- ACTIVITY LOG --------------
Observing Specialist: R.McMillan
Sleet in the afternoon, heavy clouds at the beginning of the night, and humidity all night long.  There were a few short periods where the humidity pretended it might drop, but not believably enough.
APOLLO continued to struggle to keep water moving so it wouldn't freeze.  After confirming the low water flow was adversely affecting the laser, I turned off the system's main power.
There was one wi-fi drop which affected TUI running on obsA, and many many drops affecting my laptops.
Around 4 am the 3.5m dewpoint sensor, which had been agreeing with other sensors earlier in the night, began indicating lower humidity.  I confirmed that multiple other sensors still indicated very high humidity, so I decided it was time to call the night.
                    ------- FAILURE LOG -------
              FAILURE MODE     TIME
PROG   INSTR     TI/SHU    START  FINISH  DESCRIPTION
----------------------------------------------------------------------
            ---------------- FOCUS LOG ---------------
Time  Instrument  Focus     Az  El  Temp Strc Prim  Sec  Air  filt  FWHM
--------------------------------------------------------------------------
               ------------- WEATHER LOG ----------------
                                   Wind                      Precip.or
     Time   Temp F Dewp F  MPH  Direction    Dust    Sky    Conditions
    ------------------------------------------------------------------
     16:00    33    32     16   268    (W)          cloudy   lt snow
     17:00    33    32     11   267    (W)          cloudy    humid
     18:00    32    28     14   260    (W)        mstly cldy  humid
     19:00    32    30     11   275    (W)         ptly cldy  humid
     20:00    32    30     13   270    (W)        mstly clr   humid
     21:00    31    30      9   293  (WNW)        mstly clr   humid
     22:00    31    30     11   298  (WNW)        mstly clr   humid
     23:00    31    31     13   317   (NW)        mstly clr   humid
     00:00    30    30     12   299  (WNW)        mstly clr   humid
     01:00    30    28     17   301  (WNW)        mstly clr   humid
     02:00    31    27     11   313   (NW)         ptly cldy  humid
     03:00    29    27     14   317   (NW)         ptly cldy  humid
     04:00    29    26     14   335  (NNW)        mstly cldy  humid
     05:00    29    18      9   346  (NNW)     54 mstly clr    none
     Note: the wind was coming from the azimuth listed.
     The convention used is north=0 degrees, east=90 degrees.
     The dust count is particles > 1u per 0.1 cubic feet.
              ----------  TELESCOPE SOFTWARE  ----------
Current TCC version: 1.4.2
Current HUB version: v20171231_01
Current TUI version: 3.1.8