From: Subject: 3.5m Night Log 20080822 Date: Sat, 23 Aug 2008 12:33:02 +0000 (UTC) Apache Point Observatory 3.5m Telescope Night Log Friday, August 22, 2008 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH ------------------------------------------------------------------- M.Klaene R.McMillan SPIcam, Echelle, 20:15 05:50 NA2, SH, APOLLO INST SCHED(TWILIGHT) WEATH EQUIP OBS DAY NOT USED I/ROW/DN START FINISH D B D B D B USE D B --------------------------------------------------------------------- EN02/W 20:36 05:36 0 0 0 0 2.3 6.7 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialists: R.McMillan After a long delay, we were able to get on the sky tonight with the new tertiary mount. The short news is that the essential observing tasks were completed, everything looks reasonably good, and the telescope should be ready to go. The longer news is more complicated, including some minor and/or subtle problems that shouldn't have a strong impact on observing but will need to be addressed. Note that although all instruments have had a basic checkout, only a few have seen the sky since shutdown due to limited time. I wasn't confident about the weather, so I didn't open until the sun was down and the humidity dropped a bit. For the next couple of hours, while the telescope was cooling, I was mostly trying to get the Shack-Hartman working. The control computer recently died, and although Jon and Fritz managed to get the software and electronics cards onto a new computer, it turned out the default configuration files were lost. A backup configuration file was found, but as soon as I took an image it was apparent that something was pretty wrong. I tried a few variations on the configuration and then decided to check collimation with SPIcam instead. The collimation was visibly quite far off. I discussed this with Nick over the phone and he mentioned that he was unsure about the reliability of the numbers he had obtained with the auto-collimator. Since the top end was not altered during shutdown, he suggested just going back to the old values. This made the collimation look much better. After checking donuts on both sides of focus, I concluded that it was as good as I could make it with SPIcam. A proper, more accurate check once we get the Shack-Hartmann working again would be desirable, but image quality should be good for now if not ideal. During this process I also discovered that the weather information wasn't getting to the TCC, so I called Jon Brinkmann and he got that going again. Strangely, the dome open/closed status on the weather page seems to be broken (it says the dome is closed when it's open), but the other weather indicators are working. I removed the first focus measurement from the log since it was based on incorrect numbers. Once I was satisfied with the collimation, I took a pointing model. This came out remarkably close to the old model, but there is some odd-looking behavior in the altitude which might be attributable to either the altitude motors or the new tertiary mount. This is one of the subtle problems I was referring to; it probably will not be noticeable to users of NA2 instruments, but observers using instruments with smaller fields of view may notice some inconsistency in pointing. I was considering doing throughput, but some clouds moved in. This gave me the freedom to do a task I thought was probably more important, which was to take a second pointing model with the echelle for comparison against the NA2 one. Unfortunately, I wasn't able to reduce these data with our regular software because the program wasn't looking in the right place for the images. I looked at the numbers by hand and it was apparent that a similar variation was occurring at NA1, but I wasn't certain if the direction of the errors was the same or opposite. This is important, since the same sign would suggest the problem is with the altitude axis while an opposite sign would point the finger at the tertiary. Another problem which might have a minor impact on observations involves tertiary rotation. When I first rotated from NA2 to NA1 I got a large error, which resolved on homing. A couple of hours later I moved from NA1 to TR4 and got another error, smaller but still enough to cause a problem. Later rotations on a 10-minute to half-hour timescale had no troubles. This implies that we might see trouble with rotations during the middle of the night, but so far the problems have resolved easily on homing so it should only take a few extra minutes to correct. I finished up the night by adjusting tertiary tilts for TR4 (Shack-Hartmann, if we get the instrument working again), BC1 (APOLLO), and TR3 (Fastcam). To do so, I had to figure out some of the Shack-Hartmann motor configurations by hand, but I think I got the right numbers. All three ports had reasonable pointing and needed only smallish corrections. Goals for tomorrow night's second-half observations would depend on weather. If it's photometric then throughput would be desirable; if weather is imperfect then we could do some tests of pointing repeatability and tertiary rotation. ------- 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 ---------------------------------------------------------------------- 23:45 SPICAM -25( 597) 46 66 15.4 15.7 16.1 15.3 15.4 r 1.00 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------- 16:00 61 53 2 45 (NE) 604 ptly cldy none 17:00 63 52 2 257 (WSW) 784 mstly cldy lt rain 18:00 61 53 2 190 (S) 985 ptly cldy none 19:00 63 48 8 158 (SSE) 811 ptly cldy none 20:00 62 49 10 128 (SE) 834 mstly clr none 21:00 62 44 14 131 (SE) 678 clear none 22:00 62 42 17 132 (SE) 736 clear none 23:00 61 44 18 137 (SE) 782 clear none 00:00 59 44 13 134 (SE) 712 clear none 01:00 59 45 19 128 (SE) 690 clear none 02:00 59 46 16 145 (SE) 666 ptly cldy none 03:00 57 46 13 170 (S) 666 ptly cldy none 04:00 57 47 12 145 (SE) 669 ptly cldy none 05:00 56 45 7 105 (ESE) 681 mstly clr 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: 2.9.1 Current TUI version: TUI 1.5