From: Russet McMillan Subject: 3.5m Night Log 20000424 Date: Tue, 25 Apr 2000 06:25:23 -0600 (MDT) MONDAY APRIL 24, 2000 APACHE POINT OBSERVATORY OBSERVING LOG ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT DATE START FINISH Holtzman Holtzman DIS 4/24 20:37 01:00 Gillespie McMillan Guider 4/25 01:00 03:20 Stubbs Stubbs DIS, Guider, 4/25 03:20 05:25 Echelle, S-H INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RS/DN START FINISH D B D B D B USE D B NM04/R 20:37 01:00 0 - 0 - 4.4 - 0 0 - EN01/S/D 01:00 03:20 0 0 0 0 0.1 2.2 0 0 0 UW04/R 03:20 05:25 - 0 - 0 - 2.1 0 - 0 (note: times listed include instrument change time) ACTIVITY LOG Observing Specialist: McMillan First half was clear, with seeing ranging from excellent (better than 0.7 arcseconds) to moderate (around 1.3 arcsec). With DIS in use and autocollimation turned off, we found that the guiding was excellent. Guider offsets were small when we were away from the wind and up to half an arcsecond when we were pointed near the wind. We spent a lot of time making small focus adjustments during exposures, but this may have been because the telescope temperature couldn't keep up with the rapidly changing air temperature. It is still unclear whether it's necessary to leave the autocollimation off (previous examples of image motion may have been wind-related), or whether the new focus coefficients for altitude have made any obvious difference. I had some difficulty starting up DIMM. It was necessary to restart the software again in order to fix communications with the telescope, and once DIMM was taking images of Polaris it repeatedly complained that the images were not usable and only one maximum was found. I adjusted the focus again and the images looked all right to me, with two clear maxima; I couldn't interpret all of the error messages, because they went by rather quickly. Also, for the first time that I'm aware of, the laptop apparently lost its connection with the telescope in the middle of the night. During first half, we had minor difficulties because the remote Mac running Remark crashed twice for reasons unknown. But DIS continued correctly with exposures while the connection was reestablished, and no observing time was lost. Chris Stubbs donated some of the time scheduled for UW04 to engineering so that we could get a pointing model with the new secondary sag coefficients. This is expected to produce a marked improvement in image quality at the highest and lowest altitudes, since our previous secondary tilts were adjusted only for moderate altitudes. For the pointing model, since the seeing was very good, I changed the guider binning to 2x2, and that worked without a hitch. Unfortunately, I couldn't get the new pause-for-n-seconds-after-slewing feature to work and so, with the rotator being unreliable, I had to stick with the parameter that waits for a carriage return after each slew. Both pointing models went smoothly -- the accidental one before I read in the new sag coefficients, and the real one. At 02:30 the wind veered abruptly to the east and strengthened, and the seeing immediately became much worse (2-3 arcsec), then gradually improved to about 1.3 arcsec. Once the pointing model was done, we went on to some service observing with DIS and some interesting experiments in getting Shack-Hartmann "movies" of Polaris and attempting to track lunar craters without frying any instruments. OBSERVER COMMENTS C. Stubbs (UW04): Our attempt to point at the moon was, eventually, successful thanks to Russet's insights and experience. I made a unit conversion error that "tracked" us into the hard stops, my fault. Got some initial tracking and background illumnation data. FOCUS LOG APRIL 24 2000 Wind Time Instrument Focus Az El #Temp Dir MPH filt FWHM " 20:15 DISslit 100(847) 48 73 13.3/15.3 290 3 -- 1.04" 20:20 Guider 2500 0.88" #First temp is air, second temp is telescope. WEATHER APRIL 24 2000 Wind Time Temp F Dewp F MPH Direction Dust Sky Precip. 17:01 64 20 1 259 (W) 1349 clear none 18:01 63 20 8 252 (WSW) 1519 clear none 19:01 60 17 6 269 (W) 1463 clear none 20:01 55 13 3 273 (W) 1464 clear none 21:01 55 14 4 259 (W) 1561 clear none 22:01 55 14 8 235 (SW) 1467 clear none 23:01 53 14 11 209 (SSW) 1452 clear none 00:01 53 13 5 247 (WSW) 1370 clear none 01:01 53 12 4 273 (W) 1559 clear none 02:01 54 12 0 115 (ESE) 1752 clear none 03:01 50 14 18 67 (ENE) 2257 clear none 04:01 49 8 24 65 (ENE) 2290 clear none 05:01 49 4 27 63 (ENE) 2178 clear none 06:01 48 5 20 72 (ENE) 2170 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 2.2.5. - Russet McMillan