From: Russet McMillan Subject: 3.5m Night log 20030425 Date: Sat, 26 Apr 2003 06:23:30 -0600 (MDT) Apache Point Observatory 3.5m Telescope Night Log Friday, April 25, 2003 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH -------------------------------------------------------------------- B.Gillespie R.McMillan Echelle,SH 19:45 20:35 I.Strateva I.Strateva DIS 20:37 05:35 B.Gillespie R.McMillan Echelle,SH 05:35 06:05 INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RO/DN START FINISH D B D B D B USE D B -------------------------------------------------------------------- EN01/O/D 19:45 20:35 0 0 0 0 0 0 0.8 0 0 PU02/R 20:37 05:25 0 0 0.2 0 7.4 1.2 0 0 0 EN01/O/D 05:35 06:05 0 0 0 0 0 0 0.5 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: R.McMillan Another photometric, dark night with moderate to excellent seeing -- and no high particle counts, either! Could one ask for more? Well, in fact, one could ask for a little less excitement. A number of operator errors during the afternoon checkout resulted in some hurried last-minute work to get the cals done and the telescope open for cooling before sunset. During twilight, I took the opportunity to do the first on-sky tests of the new echelle guider. That went well aside from some peculiar focus results, but I didn't realize the reason until I switched back to DIS. Among the other checkout errors there had been a mistyped command to turn on the telescope fans, and therefore all the cooling didn't do much good. The unventilated primary produced unusually high focus numbers (which would be expected) and also some hideously comatic images (which would not be expected). With Craig's help, I got the Shack-Hartmann up in a hurry and took some measurements of the nasty coma, then turned the telescope over to the observer just at the end of twilight. Later, when the telescope had come to equilibrium, I borrowed another 15 minutes to re-check the Shack-Hartmann and found a normal amount of coma. So apparently the earlier aberration was due entirely to having the primary unventilated before opening. This is a matter of some concern, since dusty conditions often force us to leave the fans off deliberately until the last minute. Dan Long suggested, based on experience of similar phenomena with the 2.5m, that parking the telescope near the horizon (which we have been doing since August to preserve the new aluminum coating) can cause a strong thermal gradient between the bottom (front) and top (back) of the primary mirror if the fans aren't run before opening. Perhaps we will have to reconsider our parking policy for the warmer season. Once we got DIS on the sky, everything worked well. Pointing was excellent, the instrument worked properly, and everything went very smoothly. The only trouble for the remainder of the night was the excessively good seeing (2 hours consistently between 0.55" and 0.85", even better than last night), which caused the guider to have some trouble recognizing stars. Drat. When the observer was all done in the morning, I finished up with one last Shack-Hartmann measurement (No more coma! What a surprise! And it only took 10 hours of cooling.) and a little more echelle slitviewer work. ------- FAILURE LOG ------- PROG INST FAILURE MODE TIME (SEGDFVO) TI/SHU START FINISH DESCRIPTION ----------------------------------------------------------------------- PU02 D T/H 00:41 00:53 S-H of nasty thermal coma ---------------- FOCUS LOG --------------- Air/Truss Wind Time Instrument Focus Az El Temp-C Dir MPH filt FWHM --------------------------------------------------------------------- 20:00 Echelle 316 ND2 1.1 20:25 SH 160 40 59 good 20:38 DISslit 200(1087) 70 46 10.0/11.0 216 9 - 1.05 20:45 NA2gdr 4000(45000) 71 48 9.7/10.9 207 15 R 0.95 00:45 SH -75 -40 59 very good 05:43 S-H -50(1243) -36 59 7.9/7.6 279 12 - wow 06:01 Echelle -17(-167) -39 57 8.1/7.5 271 10 ND2 0.95 --------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:01 53 14 6 283 (WNW) 1332 clear none 17:01 58 16 17 267 (W) 1004 clear none 18:01 56 14 7 267 (W) 925 clear none 19:01 53 13 7 286 (WNW) 923 clear none 20:01 51 13 9 268 (W) 1014 clear none 21:01 49 12 17 237 (WSW) 1114 clear none 22:01 48 12 13 252 (WSW) 958 clear none 23:01 48 12 11 236 (SW) 986 clear none 00:01 48 13 6 213 (SSW) 974 clear none 01:01 48 14 8 267 (W) 1029 clear none 02:01 47 12 10 269 (W) 896 clear none 03:01 47 12 7 247 (WSW) 825 clear none 04:01 47 12 12 293 (WNW) 928 clear none 05:01 47 13 8 265 (W) 942 clear none 06:01 47 13 12 279 (W) 975 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 > 1u per 0.1 cubic feet. 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: 2.80b Current guide software version: GIm Ctrlv4.1b4 Current TCC version: 2.6.8 Current TUI version: 0.61