Date: Thu, 17 Dec 1998 07:06:04 -0700 (MST) From: Russet McMillan Subject: 3.5m Night Log 981216 WEDNESDAY DECEMBER 16, 1998 APACHE POINT OBSERVATORY OBSERVING LOG ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT DATE START FINISH Turner Long SPIcam 12/16 18:27 19:17 Zucker Zucker SPIcam 12/16-17 19:17 00:10 Holtzmann Folcik SPIcam 12/17 00:10 05:31 INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RS/DN START FINISH D B D B D B USE D B PU01/S 18:27 19:17 0 - 0 - 0.8 - 0 0 - UW07/R 19:17 00:10 0 - 0 - 4.9 - 0 0 - NM11/R 00:10 05:31 0 - 0 - 5.4 - 0 0 - (note: times listed include instrument change time) ACTIVITY LOG (* means a trouble report has been issued or appended to) 1st half observing specialist: Dan Long The telescope was opened at 16:55 to clear skies. The night's start was a little delayed as work was being done on SPICAM to return it to operation after a problem last night which turned out to be due to an intermittent break in a video cable inside the instrument. The only casualty was a lack of biases for the lens monitoring run. There was a network slow-down between about 17:30 and 19:30 which made it tedious to get images back to UW, and caused connectivity problems for Remark which manifested themselves in messages not echoing back and/or status window failing to update. Once during this time the mc crashed but came up cleanly on restart without further difficulty, resulting in essentially no lost time. The other effect of the slow-down, was that cloud camera images got over 2 1/2 hours behind ( not terribly useful as a realtime monitor ). It finally caught up by about 22:00. The main "feature" of the first half of the night however was the dismal seeing. Before about 23:00 it was between 2.5 and 3.5 arcseconds, with one frame showing 5 arcsecond images. Between about 22:30 and 23:00 the wind shifted from easterly to more southerly, and the seeing improved to between 1.6 and 2.1 arcseconds. 2nd half observing specialist: Russet McMillan Second half was clear, with somewhat improved seeing compared to the evening. The telescope and instrument were well-bhaved, but we had some trouble adjusting the rate for driftscanning. Apparently the default values didn't work very well, and the stars were considerably trailed along the direction of scan. We had to tinker with the "fudge" parameter for quite a while before finding a value that provided good images. This was my first experience with driftscanning, so I wasn't sure what values were reasonable, but the information on the webpage about driftscanning with spicam seems to imply that the defaults are good. Perhaps some information on calculating reasonable values could be included? OBSERVER COMMENTS D.Zucker (UW07): Observations this evening were plagued again by very slow internet transfer times (intially 4+ minutes per SPIcam image, 2-3 minutes by midnight MST). We also had problems at the beginning communicating with Dan Long over REMARK. The cloud camera at one point was two hours behind, apparently because of the net difficulties. I tried pinging tycho from UW and found out that 50% of the packets were getting lost. I hope some solution to this problem can be found soon, as it has a very serious negative impact on remote observing. The seeing was another problem. It started out between 3 and 4 arcseconds (so bad that focus runs were almost pointless -- Dan Long and I couldn't tell the difference between images over a range of 300 focus steps). By about an hour before midnight the seeing had improved to 1.5-1.8 arcsec. On the plus side, the sky appeared to be clear, so my data (particularly the images from the last hour) should be useful. A. Folcik (NM11): There seemed to be two main issues with instrumentation tonight. First, for each driftscan command (with position angle specified) entered, the rotator rotated back to zero degrees first before moving to the desired position angle. Over numerous commands, this could eat up alot of time. The other problem with SPIcam itself was that for some unknown reason, the drift rate did not match up with the readout rate, thus yielding images with severe elongation and trailing effects. We had to adapt our scripts to include a rather large 'fudge factor' (= 2000 microseconds) to correct for this. An additional note is that the SPIcam software claims that 'help drift' will provide detailed info on driftscanning, however, it does not. FOCUS LOG DECEMBER 16 1998 Wind Time Inst Focus Az El #Temp Dir MPH filt FWHM " 18:00 SPICAM -225(5986) 212 55.7 0.6/3.9 76 15 g' 2.77 19:00 SPICAM -300(5863) 231 48.6 1.7/2.2 81 17 r' 1.82 22:25 SPICAM -175(5933) 323 44.6 2.9/0.5 151 13 V 2.25 23:45 SPIcam -075(6100) 323 34 2.8/1.4 160 12 V 1.30 WEATHER DECEMBER 16 1998 Wind Time Temp F Dewp F MPH Direction Dust Sky Precip. 16:01 44 24 1 197 (SSW) clear none 17:01 37 19 9 81 (E) clear none 18:01 33 18 13 63 (ENE) clear none 19:01 34 17 17 75 (ENE) clear none 20:01 35 16 18 75 (ENE) clear none 21:01 32 8 21 71 (ENE) clear none 22:01 33 4 11 112 (ESE) clear none 23:01 37 -2 10 172 (S) clear none 00:01 38 -3 15 142 (SE) clear none 01:01 37 -3 14 157 (SSE) clear none 02:01 35 14 12 178 (S) clear none 03:01 36 18 10 191 (S) clear none 04:01 35 20 8 181 (S) clear none 05:01 35 23 9 187 (S) clear none 06:01 36 23 12 204 (SSW) clear none 07:01 35 25 12 186 (S) 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 > 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: 2.42a. Current guide software version: GIm Ctrlv3.0b15. - Dan Long, Russet McMillan