Date: Mon, 15 Mar 1999 06:39:47 -0700 (MST) From: Russet McMillan Subject: 3.5m Night Log 990314 Apache Point Observatory, Sunspot, NM Sunday, March 14th, 1999 3.5-meter Night Observing Log Actual ---------------------------------------------------------------------- ASTRONOMER OBSERVER(S) INSTRUMENT DATE START FINISH ---------------------------------------------------------------------- UWGRB-Stubbs A.Diercks SPIcam/GrIm 3/14 19:32 23:58 H.Newberg G.Richards DIS 2.0-L-M 3/15 00:20 04:52 ---------------------------------------------------------------------- INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RS/DN START FINISH D B D B D B USE D B ---------------------------------------------------------------------- DD01/R 19:32 00:10 0 - 0 - 4.6 - 0 0 - UC03/R 00:10 04:52 0 - 0 - 4.7 - 0 0 - -------------- Activity Log -------------- 1st Half Observing Specialist: N.C.Hastings The telescope was opened at 16:30 MST. Very warm today. No problems encountered. During the early night the dust counts rose quite a bit. It was just barely over the limit, so due to the fact that we were getting sub-arcsecond images I decided to remain open. The highest the dust reached was 4100 in the enclosure and remained here for about 10 minutes only. It would be a good idea to CO2 clean the mirror Monday morning. All other conditions were very good during this period. Dan and I have noticed that the tower dust monitor consistently reads low. Dan has made some averages over the last few nights and it appears that it is reading 30-40% low. Dan also mentioned that the dry winter that we have had may lead to higher than average dust counts this spring and summer. Something to check in to. 2nd Half Observing Specialist: R.McMillan At the beginning of second half, the intex and telex fans had been turned off and the pressurization fans turned on because of the high dust counts. The seeing was pretty poor at this time -- >2 arcseconds Around 01:00, the exterior dust counts got low enough that I turned the fans on. The seeing improved to around 1.3 arcseconds, but it was still highly variable and would sometimes blow up. It may have been due to temperature adjustments with the fans on, but I found the focus on DIS changing widely and rapidly during the next few hours, even though the temperature sensors indicated less than a degree of change (see log). Both the slit camera and the guider showed focus deterioration, and the guider FWHM improved when I moved the secondary to optimize the slitcam focus. Given the difficulties I saw with GRIM a few weeks ago, this begs the question that the telescope itself might be more sensitive to temperature and other changes for some reason. Or it may be that this particular observing specialist is jinxed -- so far no one else has had much trouble. During the latter part of the morning, focus changes were gradual and commensurate with the temperature. OBSERVER COMMENTS G.Richards (UC03): For the most part things went quite smoothly -- with some very interesting results! FOCUS LOG March 14th 1999 Best Telescope Temp Wind Seeing Time Instrmnt Focus Az El Air/Truss Dir MPH filter FWHM" --------------------------------------------------------------------- 19:00 SPIcam -250(5989) 108 63 4.1/5.4 127 01 B 1.21" 19:10 Guider 51598(5989) 108 63 4.0/5.3 159 01 none 1.16" 20:45 Guider 48150(5936) 175 56 4.6/4.8 157 01 none 0.95" 21:45 GrIm II -090(6232) 218 76 3.9/3.9 110 06 f/5-J 1.49" 22:17 GrIm II -013(6311) 241 69 3.3/3.6 130 03 f/5-Kp 1.49" 00:30 slitcam 130(6327) 72 73 3.6/2.6 180 11 -- ? 01:30 slitcam -50(6220) 146 53 3.9/3.4 133 11 -- ? 02:00 slitcam -150(6102) 159 56 3.7/3.2 127 13 -- ? WEATHER LOG March 14th 1999 Wind Time Temp-F Dewp-F MPH Direction Dust Sky Precip ------------------------------------------------------------------ 16:01 47 10 5 221 (SW) 1444 clear none 17:01 46 11 6 268 (W) 1642 clear none 18:01 41 10 5 190 (S) 1563 clear none 19:01 40 6 0 195 (SSW) 2326 cirrus none 20:01 40 1 2 132 (SE) 2875 cirrus none 21:01 39 6 10 152 (SSE) 2065 cirrus none 22:01 38 6 2 148 (SSE) 2122 cirrus none 23:01 38 3 14 143 (SE) 2457 cirrus none 00:01 40 0 3 145 (SE) 3321 cirrus none 01:01 39 5 6 170 (S) 1564 cirrus none 02:01 39 9 10 125 (SE) 1184 cirrus none 03:01 37 8 12 178 (S) 1149 cirrus none 04:01 35 6 7 116 (ESE) 1252 clear none 05:01 36 4 10 144 (SE) 1752 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 for the particles > 1 micron per 0.1 cu.ft. 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: 2.54b4 Current guide software version: GIm Ctrl v3.0b 17.out - NCH, RM