Apache Point Observatory 3.5m Telescope Night Log Sunday, July 19, 2026 PROG PI ASTRONOMER OBSERVER(S) -------------------------------------------------------------------- AP01 S.Merkowitz R.McMillan OU02 G.Garcia G.Garcia UV01 R.Squillace R.Squillace UW01 P.Yoachim D.Meng,Z.Liu ON-SKY PROG INSTRUMENT START FINISH -------------------------------------------------------------------- AP01 APOLLO --:-- --:-- OU02 NICFPS 23:39 01:01 UV01 KOSMOS 01:36 03:58 UW01 KOSMOS 04:01 05:22 PROG SCHEDULED WEATH EQUIP OBS NOT USED I/ROW/DTN START FINISH D B D B D B D B ----------------------------------------------------------------- AP01/R 20:19 21:19 0 1.0 0 0 0.0 0.0 0 0 OU02/R 21:19 01:10 0.1 2.3 0 0 1.5 0.0 0 0 UV01/R 01:10 04:10 0.4 0 0 0 2.6 0.0 0 0 UW01/R 04:10 06:01 0 0 0 0 1.8 0.0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: R.McMillan The night began with thick clouds, nearby rain, and threat of more rain. All four dewpoint sensors appeared to be malfunctioning, so as the weather improved I struggled to figure out if the humidity was too high for safety. From the Press Fan hygrometer and the handheld Sloan unit, pluss the dryness of railings and car windshields, I estimated it was all right to open. But I did close during the instrument change and spent a while re-assessing the weather afterward before opening again, so I counted some time lost for UV01. From there the weather improved to clearer and drier, with good seeing. ------- 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 -------------------------------------------------------------------------- 23:50 NICFPS 567( 1839) 271 73 14.2 16.6 16.9 16.4 14.8 MK-J 0.74 02:02 kosmos 375( 1149) 164 50 13.6 14.2 14.7 14.0 13.5 - 0.96 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:00 61 31 4 18 (NNE) 858 cloudy lt rain 17:00 65 31 7 49 (NE) 935 cloudy lt rain 18:00 66 32 6 204 (SSW) 925 cloudy none 19:00 61 31 7 52 (NE) 947 mstly cldy none 20:00 61 31 1 196 (SSW) 955 cloudy none 21:00 59 31 9 148 (SSE) 924 cloudy none 22:00 59 31 9 138 (SE) 946 mstly cldy none 23:00 59 31 9 138 (SE) 1034 ptly cldy none 00:00 57 31 8 166 (SSE) 2867 ptly cldy none 01:00 57 30 11 148 (SSE) 1014 ptly cldy none 02:00 57 30 6 189 (S) 877 mstly clr none 03:00 57 29 2 337 (NNW) 927 mstly clr none 04:00 57 29 2 337 (NNW) 854 mstly clr none 05:00 57 29 1 228 (SW) 939 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: