Apache Point Observatory 3.5m Telescope Night Log Monday, August 17, 2026 PROG PI ASTRONOMER OBSERVER(S) -------------------------------------------------------------------- AP01 S.Merkowitz R.McMillan CU04 A.Kowalski A.Kowalski UW01 P.Yoachim D.Meng,Z.Xu NM06 W.Roberson W.Roberson,A.Abbas ON-SKY PROG INSTRUMENT START FINISH -------------------------------------------------------------------- AP01 APOLLO --:-- --:-- CU04 KOSMOS 22:54 01:09 UW01 KOSMOS 01:11 03:41 NM06 ECHELLE 03:49 06:16 PROG SCHEDULED WEATH EQUIP OBS NOT USED I/ROW/DTN START FINISH D B D B D B D B ----------------------------------------------------------------- AP01/W 19:54 20:54 0 1.0 0 0 0.0 0.0 0 0 CU04/R 20:54 01:10 0.4 1.6 0 0 2.2 0.0 0 0 UW01/R 01:10 03:45 0 0 0 0 2.6 0.0 0 0 NM06/R 03:45 06:20 0 0 0 0 2.6 0.0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: A.Townsend We had a little bit of rain and a lot of nearby storms at the start of the night. Eventually the clouds and radar cleared up and we got on sky to very nice conditions and quite good seeing--especially later in the night! 1-micron dust counts were elevated during B-half, and then the counters went offline as humidity increased. Measurements with the handheld counter were consistently around 2600, so we stayed open. No telescope or instrument problems; instrument change to echelle went smoothly tonight. ------- 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 -------------------------------------------------------------------------- 23:05 kosmos 240( 1092) 90 63 15.2 16.0 16.7 15.7 15.1 -- 1.05 01:19 kosmos 340( 1129) 40 56 14.9 14.6 15.2 14.5 14.7 -- 0.66 03:54 ecamera 414( 160) 171 82 14.1 13.9 14.5 14.0 14.1 -- 0.54 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:00 69 47 1 300 (WNW) 3455 mstly cldy none 17:00 65 45 3 96 (E) 3129 mstly cldy rain 18:00 64 47 10 110 (ESE) 3892 mstly cldy lt rain 19:00 60 47 13 111 (ESE) 3113 cloudy none 20:00 59 48 16 114 (ESE) 2942 cloudy humid 21:00 60 47 18 115 (ESE) 2350 cloudy none 22:00 60 45 16 112 (ESE) 1821 ptly cldy none 23:00 59 46 17 116 (ESE) 2300 mstly clr none 00:00 60 44 19 125 (SE) 2551 clear none 01:00 59 39 19 130 (SE) 956 clear none 02:00 58 45 17 134 (SE) 3313 clear none 03:00 58 47 17 147 (SSE) 3473 clear none 04:00 57 48 17 150 (SSE) 3757 clear none 05:00 56 48 13 145 (SE) clear none 06:00 57 49 12 161 (SSE) 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: 3.2.2