From: Subject: 3.5m Night Log 20090131 Date: Sun, 1 Feb 2009 13:33:54 +0000 (UTC) Apache Point Observatory 3.5m Telescope Night Log Saturday, January 31, 2009 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH ------------------------------------------------------------------- M.Klaene R.McMillan NA2gdr 17:40 19:10 F.Mullally F.Mullally,C.Badenes Agile 19:10 00:04 S.McCandliss B.Fleming,S.McCandliss, DIS 00:20 06:10 K.France INST SCHED(TWILIGHT) WEATH EQUIP OBS DAY NOT USED I/ROW/DN START FINISH D B D B D B USE D B --------------------------------------------------------------------- PU02/O 18:31 00:10 0 0 0 0 1.1 3.9 0 0 0.7 JH02/R 00:10 06:03 0 0 0 0 5.9 0 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: R.McMillan Another photometric night, this time with the excellent seeing that we have (occasionally) seen in Januaries past. Best measurements of the night were 0.59 arcseconds with Agile and 0.67 arcseconds with the DIS slitviewer -- I don't think I've ever seen less than 0.8 arcsec on the slitviewer before. The first half observers were delayed in arriving on-site, so I took the opportunity for some engineering work related to telescope pointing. I homed the tertiary mirror again, and got an error of 650K on B. After homing, I found the pointing to be quite good using last night's tilt numbers for NA2 (which were measured immediately after homing). Then I took a pointing model, reduced and implemented it. The RMS over the sky was 5.5 arcseconds, slightly improved from the last model, and the elongation in the altitude direction was also reduced, perhaps consistent with a moderate improvement in the altitude magnesensor numbers. Despite the lower RMS, this model had only very slight differences from the previous one, so I don't know if it will make a significant difference in the odd tracking results we've been seeing -- but it's worth a try. Once the observers arrived, first half went well mostly with Agile. Since timing was critically important, we used aacq rather than TUI control for the instrument. I had to work somewhat to keep up with focus changes for the first couple of hours, but once I got caught up we started to see excellent image quality. The only difficulty came when a star saturated due to the good seeing and the observers changed the gain to 'high' instead. This was not the correct change to increase dynamic range, as we soon figured out (we needed to set the gain to 'low') -- but I don't think that accounts for the very strange images we obtained with the 'high' gain setting. See e.g. /export/images/AgileUT090201/apofm009.00200.fits ; it looks as if the bias level is actually negative and is being truncated at 0. Second half with DIS everything was very peaceful and the observers commented often on the good seeing -- also good tracking. Was that the new pointing model, the special atmospheric stability, or the new guiding strategy I suggested? ------------- ACTIVITY LOG -------------- PROG INST FAILURE MODE TIME (STEDFNVOG) TI/SHU START FINISH DESCRIPTION ---------------------------------------------------------------------- ---------------- FOCUS LOG --------------- Time Instrument Focus Az El Temp Strc Prim Sec Air filt FWHM ----------------------------------------------------------------------- 19:14 AGILE -65( -632) 227 69 2.7 2.7 2.9 1.7 2.6 BG40 0.91 00:39 dis-slit -59( -431) 133 48 0.1 0.2 0.3 -0.5 -0.2 - 1.10 02:22 dis-slit -22( -413) 106 62 0.8 0.1 0.6 -0.4 0.5 - 1.20 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------- 16:00 37 -3 3 253 (WSW) 623 clear none 17:00 38 -8 7 334 (NNW) 477 clear none 18:00 34 -12 7 352 (N) 291 clear none 19:00 37 -9 10 322 (NW) 282 clear none 20:00 37 -10 10 302 (WNW) 286 clear none 21:00 36 -10 7 262 (W) 362 clear none 22:00 32 -5 9 331 (NNW) 658 clear none 23:00 33 0 12 311 (NW) 982 clear none 00:00 33 4 16 282 (WNW) 900 clear none 01:00 32 4 14 325 (NW) 938 clear none 02:00 33 2 11 346 (NNW) 749 clear none 03:00 33 1 7 38 (NE) 647 clear none 04:00 32 1 1 79 (E) 706 clear none 05:00 31 0 8 11 (N) 483 clear none 06:00 31 0 18 358 (N) 517 clear 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: 2.10.0 Current TUI version: TUI 1.5.1