Apache Point Observatory 3.5m Telescope Night Log Tuesday, March 17, 2026 PROG PI ASTRONOMER OBSERVER(S) -------------------------------------------------------------------- GS01 M.Crenshaw M.Crenshaw&Class OU02 Sameer Sameer ON-SKY PROG INSTRUMENT START FINISH -------------------------------------------------------------------- GS01 KOSMOS --:-- --:-- OU02 KOSMOS 03:27 06:09 PROG SCHEDULED WEATH EQUIP OBS NOT USED I/ROW/DTN START FINISH D B D B D B D B ----------------------------------------------------------------- GS01/O 19:21 01:10 5.8 0 0 0 0.0 0.0 0 0 OU02/R 01:10 07:01 3.3 0 0 0 2.3 0.2 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: A.Townsend On generator power as of this afternoon. We switched back to utility power at about 17:40. The mirror covers and the dome controller had to be reset. Restarted dataq at the end of the night. Around sunset, 1-micron dust counts rose over the limit and stayed there for most of the night. The dust finally dropped around 03:15 and we opened up to decent seeing but marginally high winds. The rest of the night went fairly smoothly, although I did have to disconnect and reconnect the ARCSAT camera in ACP in order to get the filter wheel menu to populate. ------- 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 -------------------------------------------------------------------------- 02:38 kosmos 475( 975) 250 79 9.9 8.7 9.3 8.8 9.3 -- 1.18 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:00 49 20 19 0 (N) 2588 mstly clr none 17:00 49 21 7 314 (NW) 2098 mstly clr none 18:00 49 20 3 345 (NNW) 3268 mstly clr none 19:00 47 19 9 326 (NW) 4082 mstly clr dust 20:00 47 19 10 333 (NNW) 4140 mstly clr dust 21:00 47 18 16 289 (WNW) 6193 mstly clr dust 22:00 48 18 8 319 (NW) 6834 mstly clr dust 23:00 50 21 15 298 (WNW) 4866 mstly clr dust 00:00 49 21 8 344 (NNW) 4177 mstly clr dust 01:00 50 21 10 347 (NNW) 4006 mstly clr dust 02:00 50 19 12 29 (NNE) 3954 mstly clr dust 03:00 49 19 22 27 (NNE) 4243 mstly clr dust 04:00 51 19 21 37 (NE) 1379 mstly clr none 05:00 51 18 27 68 (ENE) 1026 mstly clr none 06:00 52 18 23 58 (ENE) 554 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