Apache Point Observatory
                      3.5m Telescope Night Log
                      Friday, July 24, 2026

PROG  PI ASTRONOMER      OBSERVER(S) 
--------------------------------------------------------------------
EN02  C.Smith           R.McMillan            
EN02  C.Smith           R.McMillan            

                         ON-SKY
PROG  INSTRUMENT     START   FINISH
--------------------------------------------------------------------
EN02  ARCTIC         --:--   --:--   
EN02  ARCTIC         --:--   --:--

   PROG       SCHEDULED      WEATH     EQUIP     OBS     NOT USED
 I/ROW/DTN  START  FINISH   D    B    D    B    D    B    D    B
-----------------------------------------------------------------
EN02/R      20:16  01:10    0   4.9   0    0   0.0  0.0    0    0
EN02/R      01:10  06:04   3.6  1.3   0    0   0.0  0.0    0    0

note: scheduled times listed include instrument change time

              ------------- ACTIVITY LOG --------------
Observing Specialist: R.McMillan

Clouds in late afternoon and early evening were just beginning to thin as expected, but then an outflow came through and inspired them to make more rain.

In addition, the weather server feeding data to the website, loggers, and the TCC went down just before sunset.  This meant a much reduced chance that I could take advantage of any small improvements - I would need a very big improvement in order to feel safe to open.  I did do some ventilation at times when handheld instruments said the humidity and dust were low enough, and I checked out instruments and telescope motion.  At first the telescope seemed fine, but on closer look I found the alt controller was messed up in a strange was that the TCC could not see.  I was unable to resolve this problem.

ARCTIC continued to have high noise in the LL quadrant until around midnight, despite the extra cooling fan blowing on the instrument.



                    ------- 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    69    48      7    92    (E)   3343   cloudy   lt rain
     17:00    73    42      2   235   (SW)   3194   cloudy   lt rain
     18:00    77    45      4   215   (SW)   2482 mstly cldy   none 
     19:00    75    44      3   235   (SW)   2601  ptly cldy   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: 3.2.2