From: Subject: 3.5m Night Log 20090927 Date: Mon, 28 Sep 2009 12:45:08 +0000 (UTC) Apache Point Observatory 3.5m Telescope Night Log Sunday, September 27, 2009 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH ------------------------------------------------------------------- T.Murphy R.McMillan APOLLO 18:50 20:00 M.Gladders E.Wuyts NICFPS 20:05 00:58 T.Yan T.Yan Tspec 01:18 06:25 NST SCHED(TWILIGHT) WEATH EQUIP OBS DAY NOT USED I/ROW/DN START FINISH D B D B D B USE D B ---------------------------------------------------------------------- UW14/O 19:01 20:01 0 0 0 0.1 0 0.2 0.7 0 0 UC03/R 20:01 01:05 0 0 0 0 0 5.0 0 0 0 CU01/R 01:05 06:02 0 0 0 0 4.3 0.7 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: R.McMillan Another photometric night, with seeing that was somewhat variable but mostly good -- but we had some trouble taking advantage of it due to tracking problems. APOLLO was able to get the laser working and overcome several other difficulties to get a modest signal, which is especially valuable because it was the first night of very low libration in over a year. While tracking the moon with the video-speed guide camera, I could see tracking oscillations back and forth in the azimuth direction, coinciding with sinusoidal signals from the telescope telemetry. The amplitude was about 1 arcsec and the period 2-3 seconds. Later in the APOLLO run there was a tracking failure, cause unknown but several possibilities are under consideration. It took a few minutes to recover from this and get back to the moon for a final run. The same tracking difficulties showed up while NIC-FPS was in use, appearing as elongated star images at times when I could see the same sine wave on the telemetry. This occurred in various parts of the southeastern and southwestern sky at moderate altitudes where the telescope should be able to track well. I phoned Fritz and he made an adjustment to the PID loop; at first this seemed to produce some improvement in image quality, but later during second half the sinusoids appeared again. Interestingly, I did see the azimuth sine wave with similar frequency and amplitude on an eastern target that was tracking mostly upward, so this implies that the oscillation frequency is not dependent on the speed of azimuth tracking. The limitation on image quality made one target unreachable for the first half observer, but mostly the data were useful although degraded. ------- FAILURE LOG ------- PROG INST FAILURE MODE TIME (SEDFNVOG) TI/SHU START FINISH DESCRIPTION ---------------------------------------------------------------------- UW14 A T/H 19:46 19:51 az track failed, "not responding" ---------------- FOCUS LOG --------------- Time Instrument Focus Az El Temp Strc Prim Sec Air filt FWHM -------------------------------------------------------------------------- 18:40 APOLLO 125 510nm 1.2 20:24 NICFPS -50( 885) 74 47 14.1 14.6 13.8 12.7 13.5 H 1.04 01:30 Tspec 100 K 1.23 Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------- 16:00 66 22 10 261 (W) 1132 clear none 17:00 61 20 5 270 (W) 1230 clear none 18:00 61 21 7 277 (W) 1453 clear none 19:00 57 22 5 284 (WNW) 1613 clear none 20:00 57 20 1 236 (SW) 1559 clear none 21:00 60 19 3 285 (WNW) 1466 clear none 22:00 59 18 2 244 (WSW) 1471 clear none 23:00 59 18 5 259 (W) 1262 clear none 00:00 59 18 6 255 (WSW) 1449 clear none 01:00 59 19 5 257 (WSW) 1238 clear none 02:00 59 22 4 254 (WSW) 1012 clear none 03:00 58 22 3 219 (SW) 645 clear none 04:00 59 22 1 335 (NNW) 648 clear none 05:00 59 22 0 170 (S) 803 clear none 06:00 59 22 1 238 (WSW) 755 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