Apache Point Observatory 3.5m Telescope Night Log Friday, January 09, 2026 PROG PI ASTRONOMER OBSERVER(S) -------------------------------------------------------------------- OU04 M.Kilic M.Kilic UW11 S.Hawley S.Hawley ON-SKY PROG INSTRUMENT START FINISH -------------------------------------------------------------------- OU04 ARCTIC --:-- --:-- UW11 ECHELLE --:-- --:-- PROG SCHEDULED WEATH EQUIP OBS NOT USED I/ROW/DTN START FINISH D B D B D B D B ----------------------------------------------------------------- OU04/R 17:24 00:10 6.6 0.2 0 0 0.0 0.0 0 0 UW11/R 00:10 06:58 0 6.8 0 0 0.0 0.0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: J.Dembicky Closed tonight due to remaining ice on enclosure. A few odd computer network glitches, such as web pages not wanting to load and then a minute later all was fine and the dome cameras feeds freezing and then not wanting to refresh/reload. We also had some of the coldest weather of the season so far. Outside temps were in the -12C range. It was also a bit breezy outside as well with gust over 35MPH. Brrrrrr.... I left the enclosure parked due S to help melt the ice during the daytime. Instrument fills done at 03:00 tonight. I also noticed tonight that the new optidew sensor (the one Cary told us to use) showed and outside temp of -11.7C, Outside DP of -13.2C, Outside diff of 1.5C and a humidity (in red) of 78.1%. We are used to seeing the humidity with this kind of dew point diff around 86-87% and not at a lower reading of 78%. Perhaps the cold? We couldn't open anyway but I would have defaulted to the dew point difference over the actual displayed humidity if we could have opened. This is something the obs specs should be aware of. ------- 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 -------------------------------------------------------------------------- ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:00 21 19 4 337 (NNW) mstly cldy humid 17:00 20 18 5 18 (NNE) mstly cldy humid 18:00 19 17 13 45 (NE) mstly clr humid 19:00 18 15 16 45 (NE) clear humid 20:00 17 14 13 68 (ENE) clear humid 21:00 17 15 15 68 (ENE) clear humid 22:00 16 14 21 71 (ENE) clear humid 23:00 14 11 22 70 (ENE) clear humid 00:00 12 9 31 69 (ENE) clear humid 01:00 11 7 30 70 (ENE) clear humid 02:00 10 5 33 70 (ENE) clear humid 03:00 9 4 21 71 (ENE) 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