Apache Point Observatory 3.5m Telescope Night Log Thursday, February 26, 2026 PROG PI ASTRONOMER OBSERVER(S) -------------------------------------------------------------------- AP01 S.Merkowitz R.McMillan,T.Sutherland NM05 A.Peck A.Peck,E.Serviss,E.Nielsen CU03 A.Kowalski J.Libby-Roberts ON-SKY PROG INSTRUMENT START FINISH -------------------------------------------------------------------- AP01 APOLLO 17:54 19:07 NM05 ECHELLE 19:11 00:05 CU03 ARCTIC 00:35 06:11 PROG SCHEDULED WEATH EQUIP OBS NOT USED I/ROW/DTN START FINISH D B D B D B D B ----------------------------------------------------------------- AP01/W 18:07 19:07 0 0 0 0 0.0 1.0 0 0 NM05/R 19:07 00:10 0 0 0 0 0.0 5.1 0 0 CU03/R 00:10 06:25 0 0 0 0.4 2.2 3.6 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: A.Townsend Thin clouds all night that didn't significantly affect observations. We had pretty good seeing though! At changeover between A-half and B-half the Sec A actuator failed to move during the set inst from ECHELLE to ARCTIC: 2026-02-27 07:11:40 .tcc.0 0 tcc w Text="Collimation Failure: mir35mSec error too large to correct: devCmd=DevCmd(GalilDevice(galil), 'A=1105993; B=2004403; C=1071379; D=-26083; E=-16793; XQ #MOVE', state=done), userCmd=UserCmd('835 move 1107.9413,-215.0000,395.0000,500.0000,1218.7348', state=running, userID=1, cmdID=835, timeLim=None)" I homed the secondary which fixed the proglem and we got on sky in a little under half an hour. I restarted arcsat-user at the start of the night, and I power cycled dataq this morning since it got itself frozen again. ------- FAILURE LOG ------- FAILURE MODE TIME PROG INSTR TI/SHU START FINISH DESCRIPTION ---------------------------------------------------------------------- CU03 ARCTIC T/H 00:10 00:35 Sec A stuck ---------------- FOCUS LOG --------------- Time Instrument Focus Az El Temp Strc Prim Sec Air filt FWHM -------------------------------------------------------------------------- 17:57 APOLLO 700( 2142) 98 46 10.8 11.7 11.2 11.5 10.7 530 1.20 19:16 ecamera 519( 118) 345 50 10.3 10.4 10.7 10.2 10.2 ND2 0.77 00:43 arctic 450( 1068) 175 37 9.4 8.5 9.0 8.4 9.0 Semrock 0.88 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:00 53 27 5 249 (WSW) 272 mstly clr none 17:00 52 26 6 324 (NW) 335 mstly clr none 18:00 51 26 8 351 (N) 297 mstly clr none 19:00 52 25 12 356 (N) 243 mstly clr none 20:00 51 26 7 37 (NE) 201 mstly clr none 21:00 49 26 6 323 (NW) 303 mstly clr none 22:00 48 27 8 354 (N) 265 mstly clr none 23:00 49 22 10 3 (N) 305 mstly clr none 00:00 49 22 7 1 (N) 231 mstly clr none 01:00 49 22 13 32 (NNE) 212 mstly clr none 02:00 48 24 9 336 (NNW) 276 mstly clr none 03:00 47 20 16 14 (NNE) 190 mstly clr none 04:00 46 17 11 11 (N) 194 mstly clr none 05:00 46 6 14 24 (NNE) 158 mstly clr none 06:00 47 3 16 37 (NE) 153 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