From: Russet McMillan Subject: 3.5m Night Log 20060807 Date: Tue, 8 Aug 2006 04:10:46 -0600 (MDT) Apache Point Observatory 3.5m Telescope Night Log Monday, August 7, 2006 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH ------------------------------------------------------------------- M.Klaene G.Saurage,R.McMillan DIS, S-H, 22:30 03:30 NA2gdr INST SCHED(TWILIGHT) WEATH EQUIP OBS DAY NOT USED I/ROW/DN START FINISH D B D B D B USE D B --------------------------------------------------------------------- EN01/W 20:55 05:24 0.1 3.3 0 0 0 5.0 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialists: R.McMillan,G.Saurage The telescope was open at sunset and through most of twilight, but just as the sky got properly dark, radar showed rain near the edge of our blind spot SE of the observatory. We closed and watched the rain pass a little to the south of us. When it seemed safely past, the humidity was getting to be borderline. We took advantage of the warm telescope to make some throughput observations while the sky was clear. Seeing was mediocre in the eastern part of the sky, but we got throughput data and alignment confirmation with the new red high resolution grating (R1200) and also with the new lower resolution set (B400 and R300) for comparison. By the time we had finished that, humidity dropped into a safe range even for a cool telescope. Next we switched to the Shack-Hartmann for a collimation check and found that although the collimation wasn't bad, it was far enough off to make a correction worthwhile. In making the adjustment, we realized that the collimation had not been changed since October 2005 despite being checked nearly every month. This is almost certainly a benefit of the semi-closed loop position corrections which have kept the secondary position far more stable this year than in the past. This rounded off the first half of the night. I started second half by using the Shack-Hartmann video to check tracking stability at our worst trouble spots around the sky: low in the NW and NE for the azimuth, high in the south for the altitude. Some motion was apparent, especially at the high southern transit, but I judged it small enough to pose no serious problem for observing. I didn't adjust the tracking parameters. Next I switched back to NA2, but when I focused the guider in preparation for a pointing model, I found the focus was much more negative than expected. I remapped the gmech and tried again, with the same results. The mechanism may have slipped and should be checked during the day. I obtained a pointing model which showed only a slight change in parameters from last month, but a noticeable increase in scatter (7 arcseconds RMS). I'm pretty sure this was due to the alt magnesensors, which are always flaky but seemed worse tonight than usual. They might benefit from a remap. Orographic clouds started to form around 03:00 and by 03:30 were thick enough to impede work. The list of engineering tasks was completed anyway, so I closed up. ------- FAILURE LOG ------- PROG INST FAILURE MODE TIME (SEDFNVOG) TI/SHU START FINISH DESCRIPTION ---------------------------------------------------------------------- ---------------- FOCUS LOG --------------- Air/Truss Wind Time Instrument Focus Az El Temp-C Dir MPH filt FWHM --------------------------------------------------------------------- 22:48 DISslit 0(1140) 83 52 12.6/14.3 80 12 - 1.8 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------- 16:00 68 48 9 210 (SSW) 1840 ptly cldy none 17:00 64 50 9 190 (S) 1854 ptly cldy none 18:00 64 46 2 109 (ESE) 1659 ptly cldy none 19:00 61 47 3 87 (E) 1628 ptly cldy none 20:00 59 46 8 87 (E) 1598 ptly cldy none 21:00 58 47 11 85 (E) 2039 mstly clr none 22:00 56 49 17 87 (E) 2078 mstly clr none 23:00 55 50 13 73 (ENE) 2442 clear none 00:00 57 48 8 86 (E) 2431 clear none 01:00 57 47 7 85 (E) 2308 mstly clr none 02:00 57 47 8 91 (E) 2124 mstly clr none 03:00 58 47 5 38 (NE) 2247 ptly cldy none 04:00 58 46 6 58 (ENE) 1921 ptly 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 > 1u per 0.1 cubic feet. TELESCOPE STATUS Telescope drives operational. Current TCC version: 2.8.4 Current TUI version: TUI 1.2