From: Russet McMillan Subject: 3.5m Night Log 20000329 Date: Thu, 30 Mar 2000 05:42:17 -0700 (MST) WEDNESDAY MARCH 29, 2000 APACHE POINT OBSERVATORY OBSERVING LOG ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT DATE START FINISH Zheng Tsvetanov DIS 3/29 19:15 00:10 Szkody Szkody DIS 3/30 00:10 05:00 INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RS/DN START FINISH D B D B D B USE D B JH05/R 19:15 00:10 0 - 0 - 4.9 - 0 0 - UW02/R 00:10 05:00 0 0 0 0 2.8 2.0 0 0 0 (note: times listed include instrument change time) ACTIVITY LOG Observing Specialist: McMillan, Hastings A productive night. First half was clear with good seeing (generally 0.9-1.1 arcseconds, better than DIMM). The telescope pointing was excellent, with objects frequently coming up under the slit, and guiding was very steady. During second half, we started to get a little light cirrus, and the seeing improved even more (guider images were undersampled while DIMM was getting greater than 2 arcseconds). However, the pointing was not quite so good during second half, for unknown reasons. We had one object that didn't guide very well, possibly because of a poor choice of guide star. Windshake was also evident in a number of targets low in the southwest, at a time when the wind was approximately 15 mph due west. But these difficulties were minor, and in general the performance of the telescope was excellent. We obtained some very valuable SDSS followup data, including many spectra of objects fainter than 20th magnitude. There was some trouble with the focus early on, probably because the first command to turn on the fans had failed without being noticed, and the telescope was warm when we opened. It cooled rapidly and the focus changed by 350 microns in about an hour. Part of this is reflected in the focus log; other adjustments were made on the fly later in the night. Initial unfocused images showed very poor collimation; we did not check the collimation after the telescope was cool. OBSERVER COMMENTS FOCUS LOG MARCH 29 2000 Wind Time Inst Focus Az El #Temp Dir MPH filt FWHM " 19:15 DISslit 400(832) 243 60 4.8/6.4 275 13 -- 1.00 19:20 Guider 663 19:40 DISslit 200(616) 162 55 5.0/5.7 273 13 -- 1.03 #First temp is air, second temp is telescope. WEATHER MARCH 29 2000 Wind Time Temp F Dewp F MPH Direction Dust Sky Precip. 17:01 46 19 10 261 (W) 645 clear none 18:01 43 18 8 267 (W) 639 clear none 19:01 41 19 13 268 (W) 622 clear none 20:01 41 18 15 241 (WSW) 764 clear none 21:01 40 15 19 243 (WSW) 723 clear none 22:01 40 12 10 266 (W) 726 clear none 23:01 41 12 15 264 (W) 829 clear none 00:01 40 12 13 276 (W) 948 clear none 01:01 40 12 15 277 (W) 869 clear none 02:01 40 18 12 272 (W) 709 clear none 03:01 39 16 12 269 (W) 818 cirrus none 04:01 40 15 11 266 (W) 839 mstly clr none 05:01 38 15 11 263 (W) 860 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: 2.55b5. Current guide software version: GIm Ctrlv3.0b27. Current TCC version is 2.2.2. - Russet McMillan