Date: Thu, 17 Jun 2004 05:20:24 -0600 (MDT) From: John Barentine Subject: 3.5m Night Log 20040616 Apache Point Observatory 3.5m Telescope Night Log Tuesday, June 16, 2004 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH -------------------------------------------------------------------- A.Klypin J.Holtzman DIS 21:12 23:00 E.Turner J.Barentine SPIcam --:-- --:-- INST SCHEDULED WEATH EQUIP OBS DAY NOT USED I/RO/DN START FINISH D B D B D B USE D B --------------------------------------------------------------------- NM06/R 21:17 01:00 2.0 0 0 0 1.7 0 0 0 0 PU08/O 01:00 04:51 3.9 0 0 0 0 0 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: J.Barentine A few clouds in the sky around sunset. The night started out promising, but before reaching the halfway mark, conditions deteriorated. The NA2 guider situation was not much improved over last night, initially. The first guider image taken on the sky showed a lone, strongly elliptical star; the orientation of the ellipse was much the same as last night. gfocus runs failed immediately, as last night. I consulted with Jon Davis and tried a gmech remap, as I did last night, but the problem wasn't solved. Images taken after the remap showed a bright swath of light over about 1/3 of the detector, which Jon says is attributable to a previously unnoticed LED next to the gmech stage limit switch. This light comes on when the limit is tripped, and the stage was at the limit after the remap. Rebooting the host computer and resetting the controller, followed by a new set inst=dis, cleared the switch and solved the problem. We noted big OOF donuts in the next image. Three sequential guider focus moves of 4000 steps resulted in no change in the position or distance OOF of the donuts. Jon diagnosed the problem as a bound-up leadscrew in the guider stage mechanism. The dust spiked up to 7K counts around 22:40. I turned off the intex and telex fans and turned on the press fans, deciding the wait it out and see if it indeed was just a spike. The dust persisted, and since seeing degraded significantly after the wind shifted to the southeast around 22:20, we closed at 23:00. During the shutdown period, as we approached instrument change time, Jon H. gave up early to allow us to service the leadscrew on the guider stage motor. When I went up to DISmount, I found that the rotator had slipped significantly; what the tcc thought was a zero-degree mount rotation turned out to be almost 3.5 degrees away from zero. Jon D. and I zeroed the rotator, then backed the guider stage up far enough to lube the leadscrew. By 01:00 conditions were sufficiently safe to open. A quick look after opening showed that the seeing was pretty bad -- beyond 2 arcseconds, with occasional excursions as high as 3. Seeing requirements on the lens program left me with no targets, so I set up the Echelle to do some other service observing, but by the time I was ready with that, the dust spiked again. Throughout this time there were waves of clouds over the site and the humidity held steady near 50%. The dust counts retreated below the closure limit around 04:30; by then, there was too little time remaining before twilight to do any useful observing. ------- FAILURE LOG ------- PROG INST FAILURE MODE TIME (SEGDFVO) TI/SHU START FINISH DESCRIPTION ----------------------------------------------------------------------- ---------------- FOCUS LOG --------------- Air/Truss Wind Time Instrument Focus Az El Temp-C Dir MPH filt FWHM --------------------------------------------------------------------- 21:00 DISslit -250(1504) 190 76 17.7/21.6 244 13 - 1.29 01:21 Echelle -172(521) 315 78 14.2/15.5 163 20 Red 2.11 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:01 77 29 12 247 (WSW) 1236 PtlyCldy none 17:01 74 29 17 252 (WSW) 1307 MstlyClr none 18:01 73 27 12 237 (WSW) 1239 MstlyClr none 19:01 72 26 13 194 (SSW) 1170 MstlyClr none 20:01 66 21 14 243 (WSW) 1130 MstlyClr none 21:01 64 22 13 227 (SW) 1965 PtlyCldy none 22:01 63 23 13 221 (SW) 1945 PtlyCldy none 23:01 58 36 15 153 (SSE) 4578 MstlyCldy dust 00:01 57 37 14 129 (SE) 4267 MstlyCldy dust 01:01 58 39 22 146 (SE) 2527 MstlyCldy none 02:01 57 38 15 152 (SSE) 3008 MstlyCldy none 03:01 58 35 13 178 (S) 5042 MstlyCldy dust 04:01 57 38 16 162 (SSE) 2096 MstlyCldy none 05:01 55 40 15 146 (SE) 1461 MstlyCldy 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 Remark version: 2.85b Current guide software version: guider v4.1b4 Current TCC version: 2.7.2 Current TUI version: TUI-0.85