Apache Point Observatory 3.5m Telescope Night Log Tuesday, June 16, 2026 PROG PI ASTRONOMER OBSERVER(S) -------------------------------------------------------------------- UW01 P.Yoachim D.Meng, Z.Liu WY01 M.Brotherton M.Brotheron UW03 F.Chabour F.Chabour ON-SKY PROG INSTRUMENT START FINISH -------------------------------------------------------------------- UW01 KOSMOS 20:45 11:31 WY01 KOSMOS 11:32 01:10 UW03 KOSMOS 01:12 05:00 PROG SCHEDULED WEATH EQUIP OBS NOT USED I/ROW/DTN START FINISH D B D B D B D B ----------------------------------------------------------------- UW01/R 20:22 23:30 0 0 0 0 1.1 2.0 0 0 WY01/R 23:30 01:10 0 0 0 0 1.7 0.0 0 0 UW03/R 01:10 05:46 0 0 0 0 4.6 0.0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: R.McMillan A nice night, photometric part of the time with thin clouds at other times. Seeing was excellent at the beginning of the night but got worse when the wind shifted a little later. ARCSAT had trouble from the beginning of the night, slewing in the wrong direction when commanded by computer or hand paddle. This problem was not resolved by multiple power cycles of the control system. The PMSS dataq was well-behaved for several hours when I had time to notice it in between trips out to ARCSAT. Later I noticed that it was intermittently getting stuck and unsticking itself. Sometimes It got stuck more than once a minute so that it was recording measurements less then half the time. But then it would be okay for a few minutes at a time, or maybe even longer. ------- 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 -------------------------------------------------------------------------- 20:59 kosmos 525( 1611) 240 54 19.9 20.9 20.4 19.9 19.5 - 0.75 23:59 khigh 425( 1395) -109 51 18.9 18.4 19.0 18.2 18.4 - 1.94 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:00 72 34 4 326 (NW) 725 clear none 17:00 73 26 9 305 (NW) 570 clear none 18:00 73 28 11 322 (NW) 614 clear none 19:00 72 27 3 269 (W) 711 clear none 20:00 70 30 7 270 (W) 715 clear none 21:00 68 32 8 238 (WSW) 770 clear none 22:00 66 33 11 225 (SW) 930 clear none 23:00 66 35 10 196 (SSW) 848 mstly clr none 00:00 66 34 14 196 (SSW) 888 mstly clr none 01:00 66 35 19 200 (SSW) 1038 ptly cldy none 02:00 64 35 13 180 (S) 1131 mstly clr none 03:00 62 36 5 152 (SSE) 1392 mstly clr none 04:00 65 32 7 275 (W) 1151 clear none 05:00 64 32 6 355 (N) 1021 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