From: Russet McMillan Subject: 3.5m Night Log 20020829 Date: Fri, 30 Aug 2002 06:18:45 -0600 (MDT) APACHE POINT OBSERVATORY 3.5m Telescope Night Log Thursday, August 29, 2002 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH ------------------------------------------------------------------- Gillespie J.Davis,R.McMillan, Echslit,NA2gdr, 20:30 06:05 W.Ketzeback,C.Loomis S-H,DIS-slit,DIS INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RO/DN START FINISH D B D B D B USE D B -------------------------------------------------------------------- EN01/O 20:27 05:42 0 0 0 0 2.9 6.3 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: R.McMillan,W.Ketzeback Our first on-sky night after the shutdown had some clouds and high dust in the evening, but nothing bad enough to prevent observations. In the middle of the night we had a period of clear, apparently photometric skies and the best seeing I have ever witnessed on the Shack-Hartmann video camera (we could not take proper advantage of it, unfortunately). In the morning some cirrus moved in just in time to prevent throughput measurements of the new mirror coating. This was also the first night of on-sky training for Bill Ketzeback, our new observing specialist. We were able to open just around the end of twilight, after the installation of the altitude drive and the remapping and recalibrating of several axes. We started with a look at collimation using the echelle slitviewer, since it's on-axis. The first out-of-focus images looked rather comatic, but improved rapidly as the telescope cooled. We found the nominal focus to be fairly close to the pre-shutdown values. Eventually, without making any changes to mirrors, we were getting evenly-illuminated donuts, but with some strange features around the outer edges. Jon Davis resolved to check the vent tubes under the primary and make sure none of them are touching the glass. The Shack-Hartmann was not usable tonight because of some kind of contamination (moth bits?) over the lens array. We did not make any adjustments to collimation. For comparison against the echelle slitviewer, we tried checking unfocused images with the NA2 guider as well. We had considerable difficulty getting a good star image from the guider and finally realized that the background was quite high, with a telltale ramp of dark current in the readout direction. The guider temperature was some 20 degrees C warmer than normal. We did manage to confirm, with very short exposures, that the unfocused images looked similar to what the echelle slitviewer showed. The guider cooling will have to be worked on during the day; for tonight, it was usable for engineering purposes with exposures of 0.1 seconds. I took Bill through the steps of a guider instrument block. The first half of the data we took (the grid) showed very little change from past measurements, as expected since the guider was not altered during the shutdown. The second half of the data (the ring) showed considerable scatter in the data and a large change from the past. We suspected that this was the result of some rotator motion problems at slew speed, which had been noted during checkout. We decided not to use the new instrument block, assuming from the first data set that things had not changed significantly. Continuing with the guider parameters that were measured last year, we did a 72-star pointing model. This went very smoothly; the only difficulties occurred when subarcsecond seeing made it hard for the software to recognize a star. The first model was done in the now-standard way, with the rotator in a fixed position; we followed that with a second, shorter model that used the rotator, in order to see how much the rotation problems might affect pointing. Little difference was apparent between the two models, so we hope pointing will not be too bad. After implementing the pointing model, I adjusted the tertiary tip/tilt values for the echelle (a large change) and the Shack-Hartmann (a small change). The Shack-Hartmann video camera showed the best seeing I've ever seen on it, apparently diffraction-limited at times. It was not quantitatively measureable without the Shack-Hartmann itself, however. Then we mounted DIS and adjusted the focus and orientation of the slitviewer. We did a quick check of spectrograph collimation and orientation. The line widths on the blue side were noticeably larger than on the red, though not grossly out of focus. The grating motors positioned themselves well; only the red medium grating had to be adjusted significantly. Next we compared the focus as measured on the slitviewer with the focus on the instrument in imaging mode. A little disagreement was apparent here, but probably not very significant; the best focus value was difficult to determine because of the excellent seeing. Since the seeing was so uncommonly good, but the sky wasn't photometric enough for throughput measurements, we took the opportunity to grab a quick exposure of an odd target recently found by SDSS. The tracking was very good despite the fact that we couldn't use the guider. We went on to finish up with a DIS slitviewer instrument block. ------- FAILURE LOG ------- PROG INST FAILURE TIME S/E/G/D/O TI/SHU START FINISH DESCRIPTION ----------------------------------------------------------------------- ---------------- FOCUS LOG --------------- Air/Truss Wind Time Instrument Focus Az El Temp-C Dir MPH filt FWHM --------------------------------------------------------------------- 21:34 Echelle -75(98) 15 64 15.8/18.3 206 9 ND2 1.08 02:24 S-H -300(1464)* 169 66 13.6/14.6 221 5 - !!! 04:38 DISslit 25(850) 242 58 14.0/13.8 186 8 - 0.83 05:01 DIS(red) 75(910) 248 53 14.1/13.8 195 7 - 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: 2.6.5