From: Russet McMillan Subject: 3.5m Night Log 20030211 Date: Wed, 12 Feb 2003 06:33:44 -0700 (MST) Apache Point Observatory 3.5m Telescope Night Log Tuesday, February 11, 2003 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH ------------------------------------------------------------------- D.Lamb R.McMillan SPIcam 04:10 05:10 B.Gillespie J.Dembicky, C.Loomis S-H,guider 22:00 01:30 R.McMillan SPIcam 03:10 04:10 DIS 05:25 06:00 INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RO/DN START FINISH D B D B D B USE D B -------------------------------------------------------------------- UC01/R 18:39 00:00 0 4.3 0 0 0 1.0 0 0 0 EN01/O 00:00 05:55 0.9 0 0 0 1.5 3.5 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- 1st Half Observing Specialist: J.Dembicky John Barentine did checkout for me tonight but we closed around 17:30 due to thickening clouds. I worked on other tasks while we waited for the clouds to part (which don't look promising from the satellite image). We opened at 22:00 so that Craig could get some video of the S-H images. It was too cloudy to do any of Don Lambs data so I opted for S-H data instead. We were still under a lot of cirrus with bands of clouds moving thru, which caused the star to fade and brighten on the S-H monitor. Seeing was between 1.2 and 2.0 arc sec and variable. S-H Collimation tests Star Mag 7.5 Exposure 45s Conditions: Cirrus with passing thicker clouds Image Max Cts ------- ------- Mir132-134 2666 approx Mir135-137 2400 - 3400 star drifted Mir138-140 2200 - re-centered star Star Mag 5.9 Exposure 60s Conditions: Cirrus with passing thicker clouds Image Max Cts ------- ------- Mir142 16k Choose mag 5.9 star since counts were too low 2nd Half Observing Specialist: R.McMillan I decided to account the programs in the order scheduled, although we had actually planned to take a couple of hours at the beginning and end of the night for engineering and the middle six hours of the night for science. As it turned out, the engineering was done in the middle of the night while the clouds were thicker, and science exposures of setting objects came last when the weather unexpectedly improved late in the morning. During the SH measurements and pointing models, I estimated that the cloud extinction was between 2 and 7 magnitudes. Seeing was poor for the SH measurements, but I picked the four best images to reduce and got a recommendation to change the X tilt by -20 arcseconds and the Y tilt by +40 arcseconds, quite a large difference. I made this change and tried to get some confirmation data, but the seeing and clouds were even worse. The one image I thought was reducible recommended changes of +-8 arcseconds in both directions, which I thought was close enough given the suspect data. The collimation change could account for the large pointing offset we've had lately, although it might not be the cause of the irregular scatter in the pointing. When I reduced the pointing model data, I got an RMS of 5.6 arcseconds, larger than normal. There were no isolated outliers in the plots, but quite a number of points at middle altitudes had large corrections in the altitude direction. I reviewed the images and centroids and found no misidentifications and again, no single outlier but a significant amount of scatter. I tried removing the two worst data points, which were only slightly separated from the general population, but the results I got were substantially similar (RMS 5.1 arcseconds, similar parameter values). Since I had confirmed they were not misidentifications, I restored the two deleted points before implementing the model. There were no error messages indicating a bad magnesensor measurement during the time of the pointing model, but an MS.DUMP showing the last 15 altitude magnesensor measurements showed nearly half of those in the 10-arcsecond regime. So I think this is a genuine increase in pointing scatter related to the odd magnesensor behavior we've noted over the last few months. Despite the scatter, this pointing model (along with the change in collimation) should produce an improvement in accuracy over what we've seen for the last month or so, at least until another change occurs. After the pointing model, the clouds continued to look unpromising. I got another SH measurement (on a 4th-magnitude star!), which confirmed that the collimation was much improved. I was considering closing, but the star on the SH video brightened a little and began to look something like a 6th magnitude star. I still couldn't see anything outside except Jupiter and Arcturus, but I thought I would make an attempt at some of the science targets anyway. Gradually the sky conditions improved towards dawn. I accounted to UC01 only the time which was actually spent on the single remaining target for that program; an hour and a half of make-up science for two other programs remained accounted under EN01. ------- FAILURE LOG ------- PROG INST FAILURE MODE TIME (SEGDFVO) TI/SHU START FINISH DESCRIPTION ----------------------------------------------------------------------- ---------------- FOCUS LOG --------------- Air/Truss Wind Time Instrument Focus Az El Temp-C Dir MPH filt FWHM --------------------------------------------------------------------- 22:30 S-H -20(1030) 100 48 3.2/2.9 320 8 none 1.4 22:55 S-H -45(936) 123 62 3.1/2.7 26 5 none 1.7 03:21 SPIcam -100(813) 281 23 4.7/4.1 276 4 i' 1.4 --------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:01 40 9 9 329 (NNW) 122 Cirrus none 17:01 39 9 10 27 (NNE) 90 Cirrus none 18:01 38 2 10 6 (N) 53 Cirrus none 19:01 37 9 11 11 (N) 54 Cirrus none 20:01 37 17 13 312 (NW) 56 Cirrus none 21:01 38 14 12 354 (N) 59 Cirrus none 22:01 37 13 7 329 (NNW) 72 Cirrus none 23:01 37 14 6 7 (N) 122 Cirrus none 00:01 39 14 5 8 (N) 116 ptly cldy none 01:01 41 14 3 348 (NNW) 81 ptly cldy none 02:01 41 13 2 273 (W) 80 ptly cldy none 03:01 41 12 4 273 (W) 103 Cirrus none 04:01 39 11 5 282 (WNW) 98 Cirrus none 05:01 39 21 3 263 (W) 101 Cirrus none 06:01 39 25 0 179 (S) 111 Cirrus 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: 2.82 Current guide software version: GIm Ctrlv4.1b2 Current TCC version: 2.6.8