Date: Wed, 17 Jun 1998 06:12:19 -0600 (MDT) From: Tia Hoyes Subject: 3.5m obslog 980616 TUESDAY JUNE 16, 1998 APACHE POINT OBSERVATORY OBSERVING LOG ACTUAL ASTRONOMER OBSERVER INSTRUMENT DATE START FINISH Heckman Meurer SPICAM 6/16 19:15 01:10 Kibblewhite Casey EAGAL 6/16 01:20 05:30 INST SCHEDULED OBS WEATH EQUIP DAY NOTUSED I/RS/DN START FINISH D B D B D B USE D B JH01/R 21:55 01:10 2.2 0 1.1 0 0 0 0 0 0 UC07/O 01:10 03:34 0 2.4 0 0 0 0 0 0 0 PU01/O 03:34 04:13 0 0 0 0 0 0 0 0 0.7 (note: times listed include instrument change time) ACTIVITY LOG The telescope was open tonight at 23:00. High winds prevented opening earlier. Gerhardt Meurer was the first observer on. Comments:Due to weather (wind) we did not open until 22:51 MDST. Start up was slow, partially due to my inexperience with system. Experienced two major problems of unknown origin that redendered the run useless. 1. While pointing at std g138-31 and integrating for 300 s without guiding, stars trailed ~30" towards East or west. This was only fixed by using a guide star. This may seem like the obvious thing to do, but I am surprised that plain tracking can produce that large of an error over 5 minutes. 2. When I finally got to a science object field (Arp220), the object was nowhere to be found. I never did acquire it. The image of this field looks nothing like the finder field and nothing like my May21 exposure of this field when it was acquired successfully. Also the airmass that REMARK gave for Arp220 (RA 15 34 57.1, Dec 23 30 16 J2000) at MDST 00:30 was about x = 1.08, whereas my calculations showed that it should be at x = 1.5. The two problems are of a related positional nature I think. I do not know their cause. Here are my hypotheses: 1. I was running REMARK 2.39 and not 2.41. I was assured by my buddy Alan Uomoto that this would not be a problem since I was using SPICAM. But maybe it did cause a problem. 2. Towards the beginning of the night I used the SPICam command offset (offset 0 0.017) to move the telescope 1' northwards. That was my understanding of what offset is meant to do, and sure enough the next image seemed suitably displaced, but I could not find adequate doc on this command. Could it have changed the tracking rate? Anyway I would appreciate whatever suggestions you may have about the cause of these problems since I observe again with SPICam this weekend. Sean Casey and company were on site for the second half of the evening. We observed from the dome. Comments:First light for GSFC Instrument at K', the seeing was ~1.2". Focus tests were reasonable. Spent most of evening working on Instrument block. Still confused on instrument boresight registration. The Lens Monitoring was preempted for the visiting instrument. (* means a trouble report has been issued or appended to) FOCUS LOG JUNE 16, 1998 Best Telescope Wind Seeing Time Inst Focus Az El Temp# Dir MPH filter FWHM " 23:10 SPICAM -450(6161) 20.6 59.3 14.4/16.85 231.7 22.4 g' 1.4 02:20 EAGAL -125(6411) 258.0 80.0 12.1/13.2 268.0 19.2 K' 1.2 # The first temp is air, the second is truss, both in degrees C. WEATHER JUNE 16, 1998 Wind Time Temp F Dewp. MPH. Dir. DUST Sky Precip. 16:01 68 22 23 221 (SW) 654 clear none 17:01 71 18 21 215 (SW) 725 clear none 18:01 70 15 19 258 (WSW) 769 clear none 19:01 66 11 24 224 (SW) 1232 clear none 20:01 62 9 27 215 (SW) 1311 clear none 21:01 59 9 24 234 (SW) 1520 clear none 22:01 59 13 33 221 (SW) 2573 clear none 23:01 57 15 18 232 (SW) 2069 clear none 00:01 57 20 15 245 (WSW) 1440 clear none 01:01 56 21 16 245 (WSW) 822 clear none 02:01 55 22 14 244 (WSW) 685 partly cloudy none 03:01 53 19 16 245 (WSW) 605 partly cloudy none 04:01 52 16 18 250 (WSW) 597 partly cloudy none 05:01 52 14 17 254 (WSW) 624 partly cloudy none 06:01 50 12 21 243 (WSW) 499 partly cloudy 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: 2.41a Current guide software version:GIm Ctrl v3.0b 15.out -Tia