Apache Point Observatory 3.5m Telescope Night Log Tuesday, September 01, 2026 PROG PI ASTRONOMER OBSERVER(S) -------------------------------------------------------------------- UW06 C.O.Chandler C.O.Chandler,J.Murtagh CU05 A.Stephens A.Stephens AP01 S.Merkowitz R.McMillan ON-SKY PROG INSTRUMENT START FINISH -------------------------------------------------------------------- UW06 ARCTIC 19:41 22:05 UW06 ARCTIC 22:52 23:40 CU05 KOSMOS 01:14 02:37 CU05 KOSMOS 03:21 05:04 AP01 APOLLO 05:18 06:22 PROG SCHEDULED WEATH EQUIP OBS NOT USED I/ROW/DTN START FINISH D B D B D B D B ----------------------------------------------------------------- UW06/R 19:36 01:10 0 2.6 0 0.5 2.2 0.2 0 0 CU05/R 01:10 05:30 0 0.7 0 0 0.0 3.6 0 0 AP01/R 05:30 06:30 0 0 0 0 0.0 1.0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: H.Abbot Good weather to start the night, dust steadily rising until forcing closure at 2205. Opened up again at 22:52, but then had to close again by 23:40. Was able to open again just in time for B-half, but then closed again at 02:37. And opened again at 03:21. After this, dust finally settled to comfortable levels for the rest of the night. CU05 finished early at 05:04 and donated remaining time to AP01. NA2 guider then had issues where it looked like the lightpath was being blocked. Did a gmech remap but this didn't solve it. Light was getting to ARCTIC, just not the guider. Dismounted ARCTIC to see if there was an obstruction but there was not. After calling Amanda, tried gmech disconnDev/connDev, and light appeared to be getting through, however we had closed up again so wasn't able to test on sky. Arcsat had issues running throughout the night. Most annoying was ACP crashing over and over despite multiple PC reboots. Eventually figured out by the end of the night that ACP was crashing so consistenty because there were multiple users logged in at once. Another ARCSAT issue was that the dome wasn't closing with the 3.5m, detailed in a separate email. Another ARCSAT issue was that the scripts weren't running properly, detailed in that separate email. ------- FAILURE LOG ------- FAILURE MODE TIME PROG INSTR TI/SHU START FINISH DESCRIPTION ---------------------------------------------------------------------- UW06 ARCTIC I/U 23:10 23:40 gmech filter wheel lost and blocking lightpath ---------------- FOCUS LOG --------------- Time Instrument Focus Az El Temp Strc Prim Sec Air filt FWHM -------------------------------------------------------------------------- 20:05 arctic 282( 1373) -79 13 17.4 20.2 19.4 20.4 17.8 r 1.64 21:15 arctic 332( 1308) 9 33 16.9 18.2 18.1 17.7 16.9 CUVR 1.36 01:23 kosmos 307( 1122) 6 66 15.8 15.3 15.9 15.3 15.5 -- 0.65 05:22 APOLLO 340( 1859) -57 75 14.9 14.2 14.8 14.1 14.5 530 0.80 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:00 71 47 9 206 (SSW) 2853 mstly clr none 17:00 68 46 14 291 (WNW) 3003 mstly clr none 18:00 68 44 5 269 (W) 2520 mstly clr none 19:00 63 45 5 257 (WSW) 2741 clear none 20:00 63 45 4 200 (SSW) 2663 mstly clr none 21:00 63 45 5 205 (SSW) 2643 mstly clr none 22:00 61 46 10 158 (SSE) 3936 mstly clr dust 23:00 59 47 8 175 (S) 3495 mstly clr dust 00:00 60 47 11 154 (SSE) 4437 clear dust 01:00 60 47 8 185 (S) 3419 clear none 02:00 60 47 9 193 (SSW) 3566 clear dust 03:00 59 47 10 184 (S) 3798 clear none 04:00 58 47 8 181 (S) 2642 clear none 05:00 58 46 6 193 (SSW) 1321 mstly clr none 06:00 59 45 7 262 (W) 1080 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: 3.2.2