From: Russet McMillan Subject: 3.5m Night Log 20021019 Date: Sun, 20 Oct 2002 07:25:18 -0600 (MDT) Apache Point Observatory 3.5m Telescope Night Log Saturday, October 19, 2002 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH ------------------------------------------------------------------- C.Blake C.Blake SPIcam 00:30 06:58 B.Gillespie R.McMillan S-H 03:23 03:47 INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RO/DN START FINISH D B D B D B USE D B -------------------------------------------------------------------- PU06/O 19:19 03:19 0 5.2 0 0 0 2.8 0 0 0 EN02/O/D 03:19 03:48 0 0 0 0.1 0 0.4 0 0 0 PU06/O 03:48 06:17 0 0 0 0 0 2.5 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- 1st Half Observing Specialist: W.Ketzeback Clouds at the beginning of the night and then high humidity prevented opening the enclosure first half. 2nd Half Observing Specialist: R.McMillan When humidity dropped below 70% shortly after midnight and seemed to be settling there, we reopened. Of course, the humidity promptly rose again, but we held out while the telescope was still warm and it soon dropped. An hour later there was one more very alarming humidity spike (55% to 92% in a minute, then back down to 75% in the next five minutes). I compared our dewpoint sensor's output against that of the SDSS dewpoint sensor and found them in reasonable agreement, so I believe the spikes revealed a genuine instability in the airmass. But after that, the humidity became both lower and more stable. Since the fans were off and the heaters were on until immediately before we opened, the telescope's focus changed rapidly for the first couple of hours, starting at -50 and moving down to -150, then up to +100 (eventually drifting to +150). After the initial focus measurement, I just used the guider (and checks of each science image) to follow the focus. During this period, the target star moved fairly significantly across the detector between exposures; I think that was probably attributable to the combination of secondary twitches during each focus adjustment plus guider corrections in alt/az space for a high-altitude target. Since the focus updates and resulting motion didn't occur during exposures, there was no effect on image quality, and the drift didn't take the target too far from the center of the field. When we were able to keep up with the focus changes, seeing appeared to be fairly good, sometimes subarcsecond. Once the focus appeared to have stabilized, I borrowed some time for Shack-Hartmann measurements. There was a little trouble with the NA2 guider during the instrument change, falling in the grey area between user error and software design. This and a spate of variable seeing drew out the S-H observations a little, but I was able to get several good measurements which indicated another jump in collimation over the last few days. The web page has been updated with the latest results. The only other trouble during the night was that the cloudcam stopped scanning at UT 07:53 for unknown reasons, and I didn't realize it for a while, because I could see that the sky was still clear. (Could it have been related to my quitting the gmonitor with ^C at about the same time? Cloudcam and gmonitor are run from the same account, but I don't think there should be crosstalk.) All in all, it was a successful second half despite various alarums and confusions. ------- FAILURE LOG ------- PROG INST FAILURE TIME S/E/G/D/O TI/SHU START FINISH DESCRIPTION ----------------------------------------------------------------------- EN02 O T/S 03:19 03:23 NA2gdr running during inst change, caused TCC slowdown ---------------- FOCUS LOG --------------- Air/Truss Wind Time Instrument Focus Az El Temp-C Dir MPH filt FWHM --------------------------------------------------------------------- 00:40 SPIcam -50(546) 243 51 2.1/5.3 1 1 z' 1.4 02:43 SPIcam 75(532) 161 83 3.2/3.4 35 8 9100 0.91 03:25 S-H -75(920) 133 60 3.6/3.0 17 8 - decent --------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:01 40 35 6 104 (ESE) 181 Cloudy None 17:01 47 39 9 233 (SW) 128 Cloudy None 18:01 39 36 2 193 (SSW) 249 Cloudy None 19:01 39 36 0 245 (WSW) 287 Ptly Cldy None 20:01 39 35 1 28 (NNE) 374 Clear None 21:01 38 33 4 354 (N) 381 Clear None 22:01 35 33 1 68 (ENE) 422 Clear None 23:01 35 31 8 350 (N) 371 Clear None 00:01 36 32 8 8 (N) 398 Clear None 01:01 37 30 6 356 (N) 281 clear none 02:01 38 18 7 37 (NE) 257 clear none 03:01 39 12 11 31 (NNE) 232 clear none 04:01 35 19 10 20 (NNE) 337 clear none 05:01 37 21 6 16 (NNE) 418 mstly clr none 06:01 37 21 6 3 (N) 330 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 Primary, secondary, and tertiary mirrors in place and collimated. Primary support system operational. Mirror ventilation system in place. Telescope drives operational. Current Remark version: 2.82 Current guide software version: GIm Ctrlv4.1b2 Current TCC version: 2.6.6