Subject: 3.5m Night Log 20250210 From: cgray@apo.nmsu.edu Date: Tue, 11 Feb 2025 13:13:04 +0000 (UTC) Apache Point Observatory 3.5m Telescope Night Log Monday, February 10, 2025 PROG PI ASTRONOMER OBSERVER(S) -------------------------------------------------------------------- EN01 B.Ketzeback C.Gray ON-SKY PROG INSTRUMENT START FINISH -------------------------------------------------------------------- EN01 arctic --:-- --:-- PROG SCHEDULED WEATH EQUIP OBS NOT USED I/ROW/DTN START FINISH D B D B D B D B ----------------------------------------------------------------- EN01/W 17:53 06:41 0.1 12.7 0 0 0 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: C.Gray We were not able to open tonight due to cloud, dust, light rain, and just constant radar all around us. Engineering tasks completed: 1. Restart axis controllers 2. Restart tron 3. Restart tcc 4. Zero rotator: -0.153 5. Arctic filter wheel tests The arctic filter wheel tests because an interesting problem tonight. I tested FW2 and FW6, but FW5 should also be tested. I ran a script running through about 50 filter changes for many rotation positions of arctic. The engineering emails provides more details. In summary, FW2 was left unbalanced (filled with 5 filters) and consistently failed between mount rotations 105 - 165. Filter changes took longer to fail near 105 and 165 but was failing very early on and seemed to be at its worst at rotation 135. Filter positions 2 and 4 seemed to be the worst, but other filter positions also failed moving forwards and backwards. The wheel did NOT fail at any time outside rotations 105 - 165. It was interesting to see that there were no issues at rot 225 (when arctic is +45 deg from 180) but constant issue at 135 (-45 deg from 180). FW6 was a full wheel and heavy. It has the same failure behavior as FW, but with a slightly smaller angular range (115-155). All other positions were fine and the wheel was able to conduct more filter changes when moving backwards instead of forwards. I suspect the same issue will occur when FW2 has 6 filters. It would be good to test FW5 which is empty and light. ------- 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 42 17 17 252 (WSW) 1650 cloudy none 17:00 41 16 21 268 (W) 1281 cloudy none 18:00 41 18 19 251 (WSW) 1153 cloudy none 19:00 40 17 18 263 (W) 1308 cloudy none 20:00 40 18 26 244 (WSW) 1609 cloudy none 21:00 39 20 15 261 (W) 2435 cloudy none 22:00 39 22 21 268 (W) 2548 cloudy dust 23:00 37 27 14 250 (WSW) 7432 cloudy lt rain 00:00 36 27 19 243 (WSW) cloudy humid 01:00 35 25 13 252 (WSW) cloudy none 02:00 34 24 11 257 (WSW) cloudy none 03:00 34 25 12 251 (WSW) cloudy none 04:00 33 26 15 229 (SW) cloudy none 05:00 33 25 12 222 (SW) cloudy none 06:00 34 25 12 231 (SW) cloudy 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