Subject: 3.5m Night Log 20250925 From: dembicky@apo.nmsu.edu Date: Fri, 26 Sep 2025 12:34:25 +0000 (UTC) Apache Point Observatory 3.5m Telescope Night Log Thursday, September 25, 2025 PROG PI ASTRONOMER OBSERVER(S) -------------------------------------------------------------------- CU02 Y.Notsu Y.Notsu UW08 C.Chandler C.Chandler, M.Frissell ON-SKY PROG INSTRUMENT START FINISH -------------------------------------------------------------------- CU02 ARCTIC 21:04 01:10 UW08 ARCTIC 01:10 02:05 UW08 ARCTIC 04:55 06:07 PROG SCHEDULED WEATH EQUIP OBS NOT USED I/ROW/DTN START FINISH D B D B D B D B ----------------------------------------------------------------- CU02/R 19:04 01:10 0.2 1.8 0 0 4.1 0.0 0 0 UW08/R 01:10 06:46 2.8 0 0 0 0 2.8 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: J.Dembicky I delayed opening for about 2 hrs due to a large storm system that was moving towards us. It stalled out to our west and by 21:00 it looked like it was safe enough to finally open. At 01:20 a motion error in alt slewing down. Alt 61.5. I just changed the filter wheel and was going to a focus star. It was the first slew for the 2nd half (the drives were off when I change filter wheels). A simple axis init fixed the issue. We re-opened at 04:55 and stayed open the remainder of the night. The outside 3.5m and outside 2.5m humidity tracked much closer tonight. Inside 3.5m humidity stilled showed some discrepancy. ------- 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 -------------------------------------------------------------------------- 21:13 arctic 343( 1203) 83 72 12.6 14.2 14.6 14.1 12.6 4170 1.03 21:14 NA2gdr 35369(35369) 83 72 12.3 14.1 14.6 14.0 12.6 R 0.99 01:24 arctic 371( 1102) 264 54 12.1 11.2 11.7 10.9 11.4 CUVR 1.64 01:27 NA2gdr 35985(35985) 264 53 12.2 11.2 11.7 10.9 11.4 Clear 1.86 05:02 arctic 403( 1126) 15 56 11.5 11.0 11.5 11.1 11.2 CUVR 0.81 05:04 NA2gdr 36296(36296) 14 56 11.5 11.0 11.5 11.1 11.2 clear 0.97 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:00 61 44 5 270 (W) 527 mstly clr none 17:00 60 35 8 305 (NW) 351 mstly clr none 18:00 58 39 1 214 (SW) 428 ptly cldy none 19:00 54 41 3 258 (WSW) 495 ptly cldy none 20:00 54 41 5 267 (W) 475 ptly cldy none 21:00 55 30 6 273 (W) 288 ptly cldy none 22:00 54 40 7 257 (WSW) 423 ptly cldy none 23:00 54 42 7 215 (SW) 552 mstly cldy none 00:00 54 44 7 197 (SSW) mstly cldy none 01:00 52 43 1 147 (SSE) ptly cldy none 02:00 54 46 9 224 (SW) cloudy none 03:00 53 45 7 186 (S) cloudy none 04:00 54 45 8 245 (WSW) mstly cldy none 05:00 53 45 7 261 (W) mstly clr none 06:00 50 44 9 236 (SW) 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