Date: Thu, 12 Nov 1998 06:28:14 -0700 (MST) From: Russet McMillan Subject: 3.5m Night Log 981111 WEDNESDAY NOVEMBER 11, 1998 APACHE POINT OBSERVATORY OBSERVING LOG ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT DATE START FINISH Strauss Fan, Strauss DIS 11/11-12 18:29 23:45 Kriscuinas Magnier, Kriscuinas DIS 11/12 02:10 04:25 INST SCHEDULED OBS WEATH EQUIP DAY NOTUSED I/RS/DN START FINISH D B D B D B USE D B PU02/R 18:29 00:10 4.3 - 0.4 - 1.0 - 0 0 - UW11/R 00:10 05:06 0 0.9 0.5 2.2 0 1.3 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 Water was bled from the PMSS this afternoon. The plumbing was reconnected and the whole system retuned. All of this was done in time to open the telescope at 18:10 MST. Although the telescope had to be refocused a few times due to the telescope cooling down, the seeing was 1.0 - 1.1 arcsec and stayed that good until the clouds began to move in. The telescope was closed at 23:45, due to clouds. There's a focus shift across the red low res spectra. It's not very large, and I think the grating just needs to be reseated. 2nd half observing specialist: Russet McMillan Here are some quantitative numbers on that focus difference: when I fit a gaussian to a couple of fairly isolated lines near the top and bottom of an arc lamp spectrum, the column position of the best focus wandered, as did the difference between best and worst focus. line row best focus worst focus FWHM col FWHM col ---------------------------------------------- 194 2.13 561 3.68 276 632 1.73 267 2.57 464 Clouds of varying thickness persisted through second half. At 02:10, there was a hole that looked real enough, so I opened. Unfortunately, the first object exposure showed a strong dark current, and when I checked the temperatures both cameras were warm, especially the red one. The transfer dewar was completely empty even though it was only 12 hours since the last fill. I filled the dewar and did some forced cooling. The observers managed to get a few usable science exposures before clouds forced another closure at 04:25. During the hour and a half between filling the transfer dewar and closing, ten pounds of nitrogen were used. OBSERVER COMMENTS Michael Strauss: Tonight was an interesting night. Many thanks to those who worked hard to get the primary mirror support problems straightened out; we were not affected by them at all. The telescope pointed and guided like a dream. However, we had some real problems with DIS. We saw a strong gradient in the focus along the slit; the width of sky and arc lines in the low-resolution grating varied strongly from one end of the slit to another on the red side, while the blue side behaved itself. Rezeroing the grating didn't help. Interestingly, there was no such problem at all with the high-resolution grating. We strongly urge that the seating of the red low-res grating be examined carefully during the day. We lost roughly one hour tonight trying to diagnose this problem; we finally simply moved our objects over to the region of the slit where the focus seemed good, and observed there. Despite these problems, we observed three high-redshift quasar candidates from the SDSS data; all three turned out indeed to be high-redshift quasars! Kevin Krisciunas and Gene Magnier: Sky was good enough for spectroscopy in half of the sky for maybe 1.5 hours. Lost 1.5 hours trying to figure out why red spectra had such strange counts. Turned out to be loss of cryogens in that dewar. Hopefully dewars will both hold well tomorrow night and sky will be better. FOCUS LOG NOVEMBER 11 1998 Wind Time Inst Focus Az El #Temp Dir MPH filt FWHM " 18:20 DIS +200(6588) 153 54 5.0/6.3 210 17 r 1.1 19:30 guider 49000(6218) 179 57 5.6/5.5 210 17 R 1.1 19:30 DIS -125(6218) 180 57 5.7/5.4 206 19 r 1.1 #First temp is air, second temp is telescope. WEATHER NOVEMBER 11 1998 Wind Time Temp F Dewp F MPH Direction Dust Sky Precip. 16:01 42 32 13 228 (SW) ptly cldy none 17:01 39 30 15 206 (SSW) ptly cldy none 18:01 39 26 16 201 (SSW) ptly cldy none 19:01 41 23 13 211 (SSW) clear none 20:01 42 26 15 214 (SW) clear none 21:01 42 25 14 200 (SSW) clear none 22:01 42 27 16 195 (SSW) clear none 23:01 43 28 19 187 (S) ptly cldy none 00:01 41 30 13 179 (S) mstly cldy none 01:01 41 31 17 197 (SSW) mstly cldy none 02:01 41 32 19 186 (S) ptly cldy none 03:01 42 32 12 182 (S) ptly cldy none 04:01 41 32 15 189 (S) mstly cldy none 05:01 42 30 15 198 (SSW) mstly cldy none 06:01 42 31 11 182 (S) mstly cldy 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