From: Russet McMillan Subject: 3.5m Night Log 20000227 Date: Mon, 28 Feb 2000 06:03:24 -0700 (MST) SUNDAY FEBRUARY 27, 2000 APACHE POINT OBSERVATORY OBSERVING LOG ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT DATE START FINISH Kron Yanny, Wilhite DIS 2/27 18:52 23:58 Krisciunas Krisciunas SPIcam 2/28 00:23 05:40 INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RS/DN START FINISH D B D B D B USE D B UC10/R 18:52 00:10 0 - 0 - 5.3 - - 0 - UW07/R 00:10 05:40 0 2.5 0 0 1.7 1.3 0 0 0 (note: times listed include instrument change time) ACTIVITY LOG (* means a trouble report has been issued or appended to) First-Half Observing Specialist: Deglman Put the 2.0" slit into DIS. The Fabry-Perot people were doing more testing on their instrument. Opened at 17:25. Talked to Kevin Krisciunas and Julianne Dalcanton. UW09's time is being given to UW07. DIS biases were taken for UC10. Dome was briefly closed from 18:25 til 18:40 for quartz flats on the DIS. Ran guider for DIS. No problems until about 20 minutes of use.* When the shutter began partially blocking the field, the guiding did not actually fail but would chase spurious readings thus throwing the object well out of the slit in an unpredictable manner. Seems more likely to be merely a high usage problem rather than temperature one? Or both? Second-Half Observing Specialist: McMillan Second half had increasing clouds until we were forced to close at 03:10. Seeing was moderate (1.2-1.5 arcsec) most of the time, with occasional sub-arcsecond images from SPIcam. DIMM was generally getting better seeing than either SPIcam or the guider; the seeing obtained by the telescope seemed to be very position-dependent, but some of the strange measurements may have been a result of guider shutter problems. During the DIS observations, guiding was extremely difficult while using horizon rotation. We recommend that DIS observers avoid horizon rotation when the guider is not working properly, because objects repeatedly pop out of the slit and photons *will* be lost. If necessary for the science, we can use object rotation to move to the approximate parallactic angle for a target, without actually trying to track the parallactic angle unless the guider is available. Observations with SPIcam showed a great deal of image motion, especially in the SW (which happened to be near the wind). When we used short guider exposures (5 seconds), the guider was able to compensate well enough that images would be out-of-round but most were still usable for aperture photometry -- until the guider shutter began sticking after about two hours of good behavior. Since the night was quite warm, this is beginning to look like a problem that crops up after a certain amount of use regardless of temperature, although we never got two solid hours of good guiding out of the shutter on recent cold nights. OBSERVER COMMENTS FOCUS LOG FEBRUARY 27 2000 Wind Time Inst Focus Az El #Temp Dir MPH filt FWHM " 18:55 DISslit +85(560) -7 70 8.1/8.3 194 16 none 1.55 00:20 SPIcam -50( ) 221 64 7.5/6.9 195 27 V 1.21 #First temp is air, second temp is telescope. WEATHER FEBRUARY 27 2000 Wind Time Temp F Dewp F MPH Direction Dust Sky Precip. 17:01 49 1 11 194 (SSW) 891 lt cirrus none 18:01 45 2 18 178 (S) 663 lt cirrus none 19:01 47 2 16 175 (S) 1036 lt cirrus none 20:01 45 0 23 177 (S) 1364 lt cirrus none 21:01 46 0 22 191 (S) 1650 lt cirrus none 22:01 46 0 22 181 (S) 1525 lt cirrus none 23:01 46 -3 27 182 (S) 1602 lt clouds none 00:01 44 -3 23 195 (SSW) 1533 ptly cldy none 01:01 45 0 25 190 (S) 1314 ptly cldy none 02:01 45 2 26 196 (SSW) 1422 ptly cldy none 03:01 43 2 20 202 (SSW) 1423 mstly cldy none 04:01 42 3 14 207 (SSW) 1820 mstly cldy none 05:01 41 1 13 229 (SW) 1738 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: 2.55b5. Current guide software version: GIm Ctrlv3.0b27. Current TCC version is 2.2.2. - Frank Deglman, Russet McMillan