Date: Mon, 20 Oct 2008 13:17:20 -0000 (UTC) Subject: 3.5m Night Log 20081019 From: "Gabrelle Saurage" Apache Point Observatory 3.5m Telescope Night Log Sunday, October 19, 2008 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH ------------------------------------------------------------------- M.Drosback M.Drosback,R.Indebetouw TSPEC 18:25 01:00 M.Strauss M.Strauss,M.Shin TSPEC 01:00 06:45 INST SCHED(TWILIGHT) WEATH EQUIP OBS DAY NOT USED I/ROW/DN START FINISH D B D B D B USE D B --------------------------------------------------------------------- UV05/R 19:19 01:00 0 0 0 0.8 2.5 2.4 0 0 0 PU06/R 01:00 06:18 0 0 0 0 0 5.3 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialists: G.Saurage AzVeloScale: 579.6, 584.1; 581.8 (set to 582) Beginning of the night, all the slews to the rotator were failing (Server error too large). After testing, I determined they were only failing on rotations greater than +100 mount (thru -180 was fine). It was still bright enough so that I could see the instrument on the video camera. When it would fail it would release and swing around freely under it's own weight. Fritz got online to help. After various things, he found that the current needed to drive TSpec around was significantly higher than the previous night. The cause seems to be a near full tank of LN2; there were no other changes, the instrument was mounted the whole time. I filled it in the morning but I also topped it off in the evening. Moving the instrument manually it was heavily weighted more on one side, so much so that I could barely spin it up, and it certainly wouldn't stay there with the motors off. Fritz increased the current limit and then we had to roughly zero the rotator as it was lost after all those free rotations and controller rebooting. This whole process took almost 2 hours. Rotator worked fine the remainder of the night after changes in controller and maybe since some of the LN2 spilled out. I filled the main tank again in the morning but not the Aux tank. Mostly clear night with thin cirrus here and there; patchy clouds second half. Good to moderate seeing. ------- FAILURE LOG ------- PROG INST FAILURE MODE TIME (SEDFNVOG) TI/SHU START FINISH DESCRIPTION ---------------------------------------------------------------------- UV05 T T/H 19:19 20:10 Rotator failures ---------------- FOCUS LOG --------------- Time Instrument Focus Az El Temp Strc Prim Sec Air filt FWHM ----------------------------------------------------------------- 20:12 TSPEC 85( 578) -49 41 11.0 11.5 11.2 10.8 11.0 1.23 01:06 TSPEC 6( 398) -11 58 10.8 9.9 10.5 9.3 10.5 0.85 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------- 16:00 56 36 6 260 (W) 621 clear none 17:00 56 40 8 253 (WSW) 599 clear none 18:00 54 38 8 242 (WSW) 755 clear none 19:00 52 36 6 214 (SW) 852 clear none 20:00 52 37 9 219 (SW) 798 clear none 21:00 52 36 9 220 (SW) 787 clear none 22:00 52 36 8 217 (SW) 684 mstly clr none 23:00 51 36 1 131 (SE) 762 mstly clr none 00:00 51 36 7 184 (S) 728 clear none 01:00 52 36 12 215 (SW) 764 clear none 02:00 51 36 6 204 (SSW) 749 clear none 03:00 51 37 9 207 (SSW) 792 clear none 04:00 48 37 7 201 (SSW) 795 mstly clr none 05:00 50 37 11 181 (S) 737 mstly clr none 06:00 48 38 2 112 (ESE) 730 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 STATUS Telescope drives operational. Current TCC version: 2.9.1 Current TUI version: TUI 1.5