From: Russet McMillan Subject: 3.5m Night Log 20070605 Date: Wed, 6 Jun 2007 06:09:56 -0600 (MDT) Apache Point Observatory 3.5m Telescope Night Log Tuesday, June 5, 2007 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH -------------------------------------------------------------------- N.Chanover N.Chanover Echelle 20:00 22:03 D.Bowen D.Bowen DIS 22:07 00:54 M.Klaene R.McMillan S-H 01:00 00:20 T.Snow M.Drosback, Echelle 00:25 05:35 G.Stringfellow INST SCHED(TWILIGHT) WEATH EQUIP OBS DAY NOT USED I/ROW/DN START FINISH D B D B D B USE D B --------------------------------------------------------------------- NM01/R 20:18 22:13 0 0 0 0 1.0 0 0.9 0 0 PU06/R 22:13 01:00 0 0 0 0 2.0 0.8 0 0 0 EN01/W/D 01:00 01:25 0 0 0 0 0 0.4 0 0 0 CU06/R 01:25 04:52 0 0 0 0 0 3.5 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: R.McMillan We had thin-to-medium clouds all night long plus moderate winds out of the west which produced some windshake. Seeing was good early in the evening, moderate around midnight, and pretty poor second half. The dome shutter doors were worked on during the day, but when I spoke to Mark he wasn't certain if any sunlight got on the top end or not. With the old top end, sun exposure would affect collimation. That's probably not a concern with the new top end, but I was suspicious about collimation nevertheless. When I focused the echelle at the beginning of the night (facing east), the images looked fine. Later (observer working low in the west), I was seeing a lot of image elongation mostly in the altitude direction. When I focused DIS (low in the west), some of the images looked really strange -- possibly very comatic. The clouds at this point were too thick for the observer to see his targets, so I took a few minutes to look at a focus donut on the NA2 guider and the DIS slitviewer. Both of these instruments have their own optics and aberrations, so I wasn't certain, but I thought collimation was somewhat off, if not as bad as I feared earlier. I started setting up the Shack-Hartmann, but I wanted the telescope to cool some more before I actually took data. I handed back to the observer, and he struggled with the clouds for a portion of his time but got data during the rest. During a couple of slews just before the changeover, I saw a lot of noise from the azimuth motors on the dataq. I re-measured the velocity scale at changeover and found that it had changed from the stead 584-ish that Jack has carefully reported the last few nights, to 574. This binary behavior of the velocity scale, with apparently no relation to temperature (15 deg at midnight), makes no sense to me. I changed the number in the file to 577 and that got rid of the noise. I will re-measure tomorrow, and observing specialists will have to be diligent for a while about measuring velocity scale at least every evening and possibly every midnight until we get a better handle on what's going on. The second half observers weren't quite ready to go at changeover, so I encouraged them to take more cals while I ran the Shack-Hartmann. It took longer than the 15 minutes I anticipated because it turned out the windshake was really bad (low in the west -- so this probably accounted for a lot of the distortions I saw earlier). I thought the amount of image motion was excessive for a 20-mph wind, even with the telescope facing right into it -- and telemetry showed only moderate motion from the primary mirror, so there was some other form of forcing going on as well. I adjusted the altitude tuning parameters while watching the SH video, and seemed to find a combination which reduced the response to the wind a little. Image quality and tracking looked okay later in the night (facing east...), so I made those changes permanent. I managed to get a usable SH image set and got them reduced (with a little difficulty) to find that collimation was almost perfect. So apparently the windshake (and possibly the telescope out of equilibrium) accounted for ALL the aberrations I'd seen earlier, and sunlight on the top end had nothing to do with it. But the S-H video did allow me to diagnose what was happening anyway, so the time wasn't wasted. Once we got switched over to the echelle, everything went very peacefully -- pointing and tracking very good, image quality apparently acceptable (although seeing was getting worse, so we weren't very sensitive to small aberrations). ------- FAILURE LOG ------- PROG INST FAILURE MODE TIME (SEDFNVOG) TI/SHU START FINISH DESCRIPTION ---------------------------------------------------------------------- ---------------- FOCUS LOG --------------- Time Instrument Focus Az El Temp Strc Prim Sec Air filt FWHM ----------------------------------------------------------------------- 20:25 Echelle 221(-80) 66 56 17.3 18.29 17.06 17.83 17.34 ND2 0.75 22:25 DISslit 17(533) -123 29 17.4 17.11 16.71 17.32 17.12 - 1.35 00:05 S-H -100 00:35 Echelle 36(-332) 111 56 15.4 15.91 15.71 16.01 15.38 ND2 1.21 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ----------------------------------------------------------------- 16:00 73 35 17 269 (W) 876 ptly cldy none 17:00 66 33 8 263 (W) 932 ptly cldy none 18:00 67 32 13 258 (WSW) 967 ptly cldy none 19:00 66 25 22 252 (WSW) 1049 ptly cldy none 20:00 63 19 19 260 (W) 946 ptly cldy none 21:00 63 20 14 266 (W) 915 ptly cldy none 22:00 63 21 13 266 (W) 1004 mstly cldy none 23:00 63 22 14 263 (W) 1017 mstly cldy none 00:00 63 22 13 263 (W) 1062 mstly cldy none 01:00 62 20 15 260 (W) 1072 mstly cldy none 02:00 60 17 12 264 (W) 920 mstly cldy none 03:00 58 19 13 261 (W) 1027 mstly cldy none 04:00 57 20 13 263 (W) 1037 mstly cldy none 05:00 56 22 17 260 (W) 1082 mstly cldy none 06:00 54 24 17 264 (W) 1266 mstly 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: 2.9.0 Current TUI version: TUI 1.3