Date: Mon, 14 Dec 1998 07:17:15 -0700 (MST) From: Russet McMillan Subject: 3.5m Night Log 981213 Content-Length: 3188 SUNDAY DECEMBER 13, 1998 APACHE POINT OBSERVATORY OBSERVING LOG ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT DATE START FINISH Anderson Anderson, Fan DIS 12/13-14 18:26 00:10 Szkody Szkody DIS 12/14 00:10 05:29 INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RS/DN START FINISH D B D B D B USE D B UW04/R 18:26 00:10 0 - 0 - 5.7 - 0 0 - UW01/R 00:10 05:29 0 0 1.5 0.7 1.3 1.8 0 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: Karen Gloria The telescope was opened at 17:50. The net was quite slow until shortly after 18:00. This made it a little difficult for the remote observers to take spectral cals. Things went fairly smoothly after that. The seeing was a bit poorer than average for the first few hours of the evening, but it improved as the wind shifted from east to south. *The spectra on the blue side of dis aren't centered side to side on the chip. The image of the spectrum is shifted over to the right hand side of the chip. This is the case for both low and high resolution, just the blue camera images. We didn't take any exposures in imaging mode, so I don't know if this is also true for that mode. 2nd half observing specialist: Russet McMillan It was a dark and . . . well, not very stormy night. In fact, it was a nice clear night, even if the seeing wasn't so great. The air was cold, but the instruments were hot -- not, unfortunately, in a metaphorical sense. DIS ran out of lN2 and the red chip warmed, costing the observer several exposures of data. The blue high-res grating was also not calibrated quite correctly, which added to the confusion. After forced cooling brought the red dewar down to almost 100K, the observer started taking data again, but within an hour the dewar temperature was back up to 170K. It took two more sets of forced cools to get the temperature to stabilize, which caused gaps in some time-critical data. If the forced cools didn't wipe the chip, they could be done during exposures (if carefully calculated), which would save time. The best thing, of course, would be to find out why DIS has these episodes of overconsumption, and fix that. On the bright side, we think we've found what was causing the dark current on SPIcam. Images this evening showed a lower count rate than in the morning, but it was still significant and still showed a diffuse bright spot in one corner. When the set point of the heater was changed (making a small change in chip temperature, but a more significant change in current), the counts decreased, especially those near the bright/warm spot. Alan Diercks suggested that the temperature sensor might be hooked up to the cryo head rather than the chip, so that the heater was warming the chip erroneously. When the heater was turned off, the bright spot went away and the dark images became nice and flat. OBSERVER COMMENTS UW04 (S.Anderson): There were serious network problems early-on, with typing in REMARK message windows initially almost useless due to lags. However after the net traffic calmed down, the bulk of the 1st half went quite smoothly, with DIS, guider, telescope, etc. all generally working fine, and with the usual excellent support from APO staff--a good night. Thanks! Scott UW01 (P. Szkody): Despite warm dewar problems, I was able to obtain 22 spectra of my object being observed with ASCA. Unfortunately, the late start and gaps due to need for forced cooling episodes made a good velocity curve and desired tomogram difficult. It may become necessary to give dewar problems greater priority for fix under engineering nights to maintain efficient use of the telescope. FOCUS LOG DECEMBER 13 1998 Wind Time Inst Focus Az El #Temp Dir MPH filt FWHM " 18:05 slitcam -100(6160) 237 66 1.9/4.2 82 7 none 1.2 18:20 guider 59500(6183) 202 56 1.8/3.6 79 8 none 1.4 #First temp is air, second temp is telescope. WEATHER DECEMBER 13 1998 Wind Time Temp F Dewp F MPH Direction Dust Sky Precip. 16:01 38 15 2 242 (WSW) clear none 17:01 36 16 0 247 (WSW) clear none 18:01 35 14 6 82 (E) clear none 19:01 37 6 8 88 (E) clear none 20:01 36 4 10 122 (ESE) clear none 21:01 38 -6 10 159 (SSE) clear none 22:01 34 9 4 189 (S) clear none 23:01 33 11 2 234 (SW) clear none 00:01 31 7 4 152 (SSE) clear none 01:01 32 8 8 173 (S) clear none 02:01 32 5 9 168 (SSE) clear none 03:01 31 6 10 175 (S) clear none 04:01 32 4 7 179 (S) clear none 05:01 33 4 7 148 (SSE) clear none 06:01 32 5 12 164 (SSE) clear none 07:01 32 5 12 174 (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. - Karen Gloria, Russet McMillan