Apache Point Observatory 3.5m Telescope Night Log Thursday, August 20, 2026 PROG PI ASTRONOMER OBSERVER(S) -------------------------------------------------------------------- UW04 C.Chandler C.Chandler, I.Chow GS02 D.Gies A.Chaturvedi ON-SKY PROG INSTRUMENT START FINISH -------------------------------------------------------------------- UW04 ARCTIC 00:55 01:16 GS02 ECHELLE 01:16 06:20 PROG SCHEDULED WEATH EQUIP OBS NOT USED I/ROW/DTN START FINISH D B D B D B D B ----------------------------------------------------------------- UW04/R 19:51 01:10 0.0 4.6 0 0.5 0.3 0.0 0 0 GS02/R 01:10 06:22 0 0 0 0 5.2 0.0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: J.Dembicky My blue Quartz was bad and produced a bad IOL data point. The red looked fine. The blue image had some horizontal brighter/darker banding present (blueflat.0002.fits). I retook just the blue data. Secod image looked similiar but the IOL was correct at ~35 instead of some crazy large number. I had a altitude drive run-a-way tonight and it hit the upper limit switch. Physically moving it off the switch and then resetting the controller fixed the issue. Separate email sent to engnineering staff. The tertiary mirrors moved properly from NA2 to midway to Echelle. Clouds kept us closed for almost the enitre first half of the night. Second half had remaining clouds but better skies. No other issues tonight. ------- FAILURE LOG ------- FAILURE MODE TIME PROG INSTR TI/SHU START FINISH DESCRIPTION ---------------------------------------------------------------------- UW04 ARCTIC T/H 00:25 00:55 Alt drive ran away to upper limit on slew. 1Hz clock signal loss after run-a-way. Axis controller needed to be reset to fix both issues. ---------------- FOCUS LOG --------------- Time Instrument Focus Az El Temp Strc Prim Sec Air filt FWHM -------------------------------------------------------------------------- 01:05 arctic 400( 1352) 20 57 18.5 18.1 18.4 18.1 18.2 SDSS_r 1.40 01:24 ecamera 361( 304) -59 83 19.0 18.1 18.5 18.1 18.4 ND1 0.80 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:00 65 38 6 154 (SSE) 681 cloudy lt rain 17:00 68 36 3 105 (ESE) 703 cloudy none 18:00 69 38 13 126 (SE) 1083 cloudy none 19:00 67 40 8 120 (ESE) 1224 cloudy none 20:00 67 39 16 125 (SE) 1241 cloudy none 21:00 67 40 13 122 (ESE) 1964 cloudy none 22:00 67 41 13 114 (ESE) 2303 cloudy none 23:00 67 41 8 97 (E) 2909 cloudy none 00:00 66 41 12 113 (ESE) 2970 ptly cldy none 01:00 65 40 6 97 (E) 2754 ptly cldy none 02:00 64 40 6 353 (N) 2473 ptly cldy none 03:00 65 39 3 8 (N) 2242 ptly cldy none 04:00 65 39 7 6 (N) 1657 ptly cldy none 05:00 64 39 10 85 (E) 2928 mstly clr none 06:00 65 39 7 97 (E) 3420 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: