From: Subject: 3.5m Night Log 20090130 Date: Sat, 31 Jan 2009 14:20:31 +0000 (UTC) Apache Point Observatory 3.5m Telescope Night Log Friday, January 30, 2009 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH ------------------------------------------------------------------- T.Murphy R.McMillan APOLLO 17:50 18:40 D.Haggard D.Haggard,K.Arraki DIS 20:30 00:05 N.Chanover N.Chanover,C.Miller, Agile 00:15 06:30 B.Edmonds INST SCHED(TWILIGHT) WEATH EQUIP OBS DAY NOT USED I/ROW/DN START FINISH D B D B D B USE D B --------------------------------------------------------------------- UW17/O 17:43 18:43 0 0 0 0 0 0.2 0.8 0 0 UW07/R 18:43 00:10 0 0 0 0.6 2.1 2.7 0 0 0 NM01/R 00:10 06:03 0 0 0 0 5.9 0 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: R.McMillan A beautiful photometric night, poor seeing during first half that improved during second half. I didn't record the APOLLO focus because I was distracted, and didn't record the DIS focus because I did it on the fly with faint targets after some delays getting started (see below). In both cases I estimated seeing was worse than 2 arcseconds and variable. Second half started out a little better, then later there were some periods of subarcsecond seeing. The tertiary was homed in the afternoon before starting the night with APOLLO. Encouragingly, the pointing with APOLLO was quite close to what it was a month ago, before the current crop of pointing problems began. However, there was significant tracking drift. This was in a part of the sky that shouldn't be very tricky for tracking (southwest, alt around 40), and there were also complications of variable seeing and some operator errors. So I had the sense that there was probably some poor tracking attributable to the telescope, but I wasn't positive. When we switched to NA2, the tertiary seemed to move correctly but pointing was very bad -- more than 3 arcminutes off, in a direction that matched neither altitude nor azimuth. Mark was present in the control room and we took a little extra time for diagnosis rather than simply fixing the pointing as quickly as possible. We found that tonight's pointing was more similar to Wednesday night's than to Thursday night's, but all of those previously measured tilt values put the star well off center tonight. We homed the tertiary (only five hours since previous home), obtaining a position error of 700K steps on B; after that, the pointing was even more similar to Wednesday night's numbers, but still not at all centered. We had some discussion about whether the change in pointing was really consistent with 700K steps of tilt, then I just adjusted the tertiary to fix it. Starting from Wednesday night's position, tonight's change was -350 in Xtilt and +500 in Ytilt. Tracking seemed pretty good with DIS so far as we could tell with faint targets and mostly-empty fields. Almost all of these targets were at low altitude in the west or east, which tends to be a less-sensitive portion of the pointing model. It was hard to judge the pointing with Agile accurately, because the observers were tracking a solar-system object with non-sidereal rates. However, a pattern was apparent where the object held position quite well until it was within 2 hours of transit; then the observers had to start making adjustments. This pattern is more likely to be due to the telescope or pointing model than to the object's very slow non-sidereal velocity. ------------- ACTIVITY LOG -------------- PROG INST FAILURE MODE TIME (STEDFNVOG) TI/SHU START FINISH DESCRIPTION ---------------------------------------------------------------------- UW07 D T/H 18:55 19:30 pointing probs, homed tert ---------------- FOCUS LOG --------------- Time Instrument Focus Az El Temp Strc Prim Sec Air filt FWHM ----------------------------------------------------------------------- 18:17 dis-slit -100( -218) 138 56 4.6 5.5 5.0 4.4 4.3 - 1.50 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------- 16:00 39 5 7 189 (S) 905 clear none 17:00 36 4 6 110 (ESE) 732 clear none 18:00 33 3 12 87 (E) 856 clear none 19:00 36 0 2 157 (SSE) 783 clear none 20:00 34 1 3 187 (S) 803 clear none 21:00 34 0 9 151 (SSE) 662 clear none 22:00 33 -4 8 125 (SE) 485 clear none 23:00 32 -6 7 164 (SSE) 364 clear none 00:00 35 -10 8 182 (S) 396 clear none 01:00 35 -10 8 183 (S) 358 clear none 02:00 34 -11 10 183 (S) 282 clear none 03:00 33 -11 5 187 (S) 242 clear none 04:00 33 -12 7 187 (S) 202 clear none 05:00 32 -12 8 182 (S) 362 clear none 06:00 32 -14 10 181 (S) 658 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 STATUS Telescope drives operational. Current TCC version: 2.10.0 Current TUI version: TUI 1.5.1