Apache Point Observatory 3.5m Telescope Night Log Monday, April 20, 2026 PROG PI ASTRONOMER OBSERVER(S) -------------------------------------------------------------------- AP01 S.Merkowitz R.McMillan,T.Sutherland UW06 A.Heinze A.Heinze UW02 B.Benda B.Benda ON-SKY PROG INSTRUMENT START FINISH -------------------------------------------------------------------- AP01 APOLLO --:-- --:-- UW06 ARCTIC 21:08 01:07 UW02 ECHELLE 01:12 05:39 PROG SCHEDULED WEATH EQUIP OBS NOT USED I/ROW/DTN START FINISH D B D B D B D B ----------------------------------------------------------------- AP01/R 19:46 20:46 1 0 0 0 0.0 0 0 0 UW06/R 20:46 01:10 0.5 2 0 0 0.7 1.2 0 0 UW02/R 01:10 06:18 0 0 0 0 5.1 0.0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: T.Sutherland Nearby radar returns kept us closed at the start of the night. Things more or less cleared by the time UW06 was finished with cals. Closed at 21:50 due to radar popping up with some light rain. Reopened at midnight on the dot once clouds and radar went away. Weather summary webpage crashed and wouldn't load/refresh around midnight. It took about 40 minutes to resolve itself. Crashed again around 1:30am, around the same time TUI crashed for me. Nightlog focus script was failing (timed out) at 1:21am. I disconnected from TUI on ObsA at this time, since the slitviewwer also wasn't refreshing. I could not log back into tui on obsA. Per Amanda's recommendation, I made sure Wifi was on (it was off) and unplugged the 10.75.XX cable form ObsA and that seemed to fix it. See PR2288. Restarted dataq at 2:30am. No morning iol, cals were being taken. Quiet night with no telescope or instrument problems. ------- 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 -------------------------------------------------------------------------- 21:15 arctic 371( 1123) 6 38 8.5 11.4 11.9 11.5 8.9 CUVR 1.93 00:08 arctic 376( 986) -25 44 8.4 8.4 9.1 8.3 8.2 CUVR 1.35 01:23 ecam 542 -34 56 7.7 7.6 8.3 7.6 7.6 ND1 0.86 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:00 61 32 11 247 (WSW) 1639 mstly clr none 17:00 54 28 11 260 (W) 1762 mstly clr none 18:00 55 28 9 240 (WSW) 1802 mstly clr none 19:00 54 30 12 266 (W) 1915 mstly clr none 20:00 50 30 8 263 (W) 1856 mstly clr none 21:00 48 34 2 194 (SSW) 1448 ptly cldy none 22:00 46 39 6 167 (SSE) ptly cldy lt rain 23:00 47 37 4 191 (S) mstly clr none 00:00 47 38 12 191 (S) 1482 clear none 01:00 45 38 8 190 (S) clear none 02:00 46 41 11 194 (SSW) clear none 03:00 46 41 9 232 (SW) clear none 04:00 46 40 11 236 (SW) clear none 05:00 46 38 9 262 (W) 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