Apache Point Observatory 3.5m Telescope Night Log Tuesday, January 20, 2026 PROG PI ASTRONOMER OBSERVER(S) -------------------------------------------------------------------- WY01 M.Brotherton M.Brotherton GS01 M.Crenshaw J.Falcone, M.Davis UW02 P.Yoachim Z.Liu, Z.Xu ON-SKY PROG INSTRUMENT START FINISH -------------------------------------------------------------------- WY01 KOSMOS 17:33 20:02 GS01 KOSMOS 20:04 03:34 UW02 KOSMOS 03:38 06:21 PROG SCHEDULED WEATH EQUIP OBS NOT USED I/ROW/DTN START FINISH D B D B D B D B ----------------------------------------------------------------- WY01/R 17:33 20:13 0 0 0 0 0.7 1.9 0 0 GS01/R 20:13 04:10 0 0 0 0 8.0 0.0 0 0 UW02/R 04:10 06:55 0 0 0 0 2.8 0.0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: J.Dembicky So the Echelle ThAr was dim again this afternoon. The Echelle slitviewer image also looked strange. I checked the voltage on the power supply and I think it was around 15.2V. I did the Cary bounce trick (I might have moved the potentiometer slightly) and it was reading around 16V. I took another slitview image (still bad) and ThAr (bad). I then moved the cal mirror to sky, took a slit image (looked normal) then back to Lamps with the ThAr on and then took a slitview image (looked normal now). I tried another ThAr and things looked normal again. So it appears the Cal mirror was mis-positioned and not an issue with the ThAr lamp. Cary should check the voltage is properly set as I may have slightly moved the potentiometer in the process. I sent him a private email. We had Aurora activity again tonight, this time red aurora around 20:30 due east! I saw what appeared to be passing waves of red "clouds" in the all sky camera covering the entire sky at times, especially later in the night around 2AM. No telescope issues tonight. ------- 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 -------------------------------------------------------------------------- 18:24 klow 490( 768) 137 54 1.4 3.6 3.8 3.2 1.6 -- 1.30 20:17 khigh 480( 636) -46 54 1.9 1.1 2.3 1.4 1.5 -- 0.78 03:54 kosmos 480( 608) 229 72 2.5 0.7 1.5 1.1 1.8 -- 0.98 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:00 37 9 7 329 (NNW) 942 clear none 17:00 35 9 6 271 (W) 677 clear none 18:00 35 10 12 319 (NW) 237 clear none 19:00 36 5 9 285 (WNW) 276 clear none 20:00 36 8 11 352 (N) 489 clear none 21:00 34 9 12 344 (NNW) 433 clear none 22:00 35 8 5 359 (N) 396 clear none 23:00 36 6 7 331 (NNW) 294 clear none 00:00 36 7 13 351 (N) 354 clear none 01:00 34 10 13 352 (N) 550 clear none 02:00 34 9 12 3 (N) 374 clear none 03:00 35 4 11 17 (NNE) 322 clear none 04:00 37 -4 19 17 (NNE) 369 clear none 05:00 40 -13 19 31 (NNE) 119 clear none 06:00 38 -12 10 75 (ENE) 164 clear 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