From: Russet McMillan Subject: 3.5m Night Log 20030405 Date: Sun, 6 Apr 2003 07:03:56 -0600 (MDT) Apache Point Observatory 3.5m Telescope Night Log Saturday, April 5, 2003 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH -------------------------------------------------------------------- A.Seth A.Seth SPIcam 23:15 06:45 INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RO/DN START FINISH D B D B D B USE D B -------------------------------------------------------------------- UW01/R 19:20 05:51 1.0 2.9 0 0 5.6 0 0 0 0 note: scheduled times listed include instrument change time Evening start time is MST; Morning end time is MDT ------------- ACTIVITY LOG -------------- Observing Specialist: R.McMillan A dust episode started around sunset; we could observe sunspots without hurting our eyes, always a bad sign. High winds and high dust kept us closed for a substantial portion of first half. The tower dust counter was reading lower values than the enclosure dust counter or the handheld spare, but eventually it dropped low enough to open. Seeing was poor for a few hours, degrading to bad later on as the wind shifted north. The new focus algorithm did not seem to cope very well with the springtime routine of having fans off until very shortly before opening and focusing. I'll have to take it back to the drawing board. After the evening cirrus and dust clouds had passed, the skies were mostly innocent of water-vapor formations but did show a variety of passing haze, possibly dust-related. We had some excitement on the first science target when a 20-minute exposure showed star trails almost 10 arcseconds long. It was a surprise because the magnesensor readings were good, the telescope believed it was exactly where it wanted to be on all three axes, and the guide star had kept position perfectly throughout the exposure. Then I noticed that the fainter stars in the guider field had moved, and I realized we were actually guiding on a slow asteroid! This is the first time that's ever happened as far as I know. The question is, how to account for the time? The telescope was working properly, so it's not an equipment problem. Weather, maybe? ------- 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 --------------------------------------------------------------------- 23:28 SPIcam -100(91)* 145 58 -0.1/2.5 266 25 6629 1.55 23:32 NA2gdr -1683(47316) 146 58 -0.2/2.4 267 22 R 1.7 04:33 SPIcam 250(446)* 266 34 -2.6/-2.8 343 11 6607 2.59 05:31 Echelle 378(-649)* 144 65 -3.7/-3.4 309 16 ND1 2.25 * New focus algorithm has moved the zero points; they will be adjusted to compensate when (and if) the algorithm is made permanent. --------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:01 47 4 17 248 (WSW) 1282 cirrus none 17:01 46 3 30 247 (WSW) 1311 cirrus none 18:01 43 -3 32 267 (W) 2112 cirrus none 19:01 40 -3 33 250 (WSW) 3833 cirrus dust 20:01 39 -4 32 243 (WSW) 3348 cirrus dust 21:01 37 2 34 266 (W) 2608 cirrus dust 22:01 35 7 24 289 (WNW) 3199 mstly clr dust 23:01 33 12 19 271 (W) 1633 mstly clr none 00:01 31 13 28 269 (W) 944 mstly clr none 01:01 30 14 14 266 (W) 830 mstly clr none 03:01 29 12 20 286 (WNW) 818 mstly clr none 04:01 27 9 12 284 (WNW) 678 mstly clr none 05:01 27 9 16 319 (NW) 983 mstly clr none 06:01 25 6 17 322 (NW) 681 clear none 07:01 26 5 14 311 (NW) 585 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 Primary, secondary, and tertiary mirrors in place and collimated. Primary support system operational. Mirror ventilation system in place. Telescope drives operational. Current Remark version: 2.80b Current guide software version: GIm Ctrlv4.1b4 Current TCC version: 2.6.8