Date: Sun, 12 Sep 1999 07:44:26 -0600 From: "s. a. snedden" Subject: 2.5m obslog 990911 (MJD 51433) Saturday September 11, 1999 (MJD 51433) Apache Point Observatory SDSS 2.5m Observing Log Tonight's Observing Team: Dan Long (APO) Steph Snedden (APO) Connie Rockosi (UC) Francisco Castander (UC) John Peoples(FNAL) Scott Burles (UC) David Schlegel (PU) Robert Lupton (PU) Michael Strauss (PU) News flash: Off-equatorial scanning success!! Spectroscopy success!! Tonight we planned to do an off-equatorial scan. If seeing and weather permitted, we would do a long scan. Otherwise, we would switch to spectroscopy. As the night progressed, the weather and seeing improved so that it was photometric and 1arcsecond to sub-arcsecond seeing by midnight. We kept the imager on until 03:00, then switched to spectroscopy. We were on the sky at 22:30, as soon as possible after Connie finished working on the imaging camera. An on-equator scan was started at 22:45 (run 942). The coordinates were read into the headers correctly tonight. Focus was -1900. The rotator required no extra tweaking. At 23:30, we started an off-equatorial scan, on the same strip as last night (76 N, starting at lambda=126). Run 943 contains lskip and multilskip data. Focus was -1790 and the rotator had to be tweaked by +.019 deg. The seeing and weather improved at midnight. After Michael talked to Jim Gunn, it was decided to try for a long scan. The seeing was subarcsecond from about 00:30-01:30 (although the DIMM reported slightly higher values...1.0-1.5 arcsec). The long scan is run 944, and ran until 02:30, when seeing began to deteriorate. Too bad we don't have the PT tonight. We were all very happy with our success and ate pie and ice cream (thanks, Michael). By 03:30, we had swapped the imaging camera for spectro cartridge 4 holding plate 198 and were ready for spectroscopy. We went to an fk5 star and on the first try got it in the guide fiber. Focus was found to be +1525. A rotator offset of 180 arcsec was needed to acquire all guide stars in their fibers. We then started taking 15 minute guided exposures. The exposures showed some emission-line objects. Seeing continued to deteriorate, wind shifted to the north and skies became partly cloudy. There was also a bug discovered while taking the exposures...see the problem log below. Four 15 minute exposures were taken, then calibrations and sky. Overall, spectroscopy was a success. We called it a very good night at 06:30. Problem Log: * Note that the focus data taken last night indicates the focal plane is tilted, according to Jim Gunn. A shim should take care of this. Column 6 shows the largest FWHM, and reflects this problem. * T-bar bellows to dewar 5 lost pressure at about 21:45. A line may have been bumped while frozen condensate was being removed from lines in the camera? The pressure dropped to 15 psi. Connie brought the pressure back up in stages, with the telescope at zenith, so as not to move the T-bars too suddenly. * We lost about 2 hours of DIMM data. We had clouds, and afterward, we had to recenter Polaris on the CCD. * The north doghouse paddle was slightly jammed so that we were not able to move in azimuth when we opened up. Once we discovered where the problem was, a light tap freed it up. * The exposure time counted down to zero then continued to negative values at the end of the spectro exposures and the shutters wouldn't close. A temporary fix was made by forcing the mechanicals to stop the exposures & close the shutters, or by power-cycling the mechanicals on spectro 2. Scott thinks these problems are caused by a bug in goStare. * As French warned us, we had only one Ne lamp, two Hg-Cd lamps and all four incandescents. Notes: * Robert made v. 13.1 of astroda the current version, since there were problems with the v. 13.2 not reading coordinate information to the headers. * The tapes from last night's run are stored on the shelf in the control room. If a set needs to be shipped to FNAL, please notify Steph. LN2: Spectro 1 dewar filled 21:00, 07:00 Spectro 2 dewar filled 17:00, 03:00 Imager 180-l dewar swapped at 03:00 Weather: Mostly cloudy at twilight, clearing to apparently photometric conditions by 00:30 then partly cloudy after 04:00. DIMM seeing improved from 1.5" to 1.2" at 00:30, then deteriorated after 02:00, approaching 4" by morning twilight. Winds ranged from calm to 10 mph and were out of the W until 03:00, then shifted from the N. Humidity was low, ranging from about 35% to 50%. The dust particle density stayed below 50 particles/ft^3. Settings: * Imager counterweight setting: 680 * Cartridge plus corrector counterweight setting: 270 * Imager focus: -1790 * Spectro focus: 1525 * migs & galils: Start of the night: prim stat 0 1 I Received=" 1, 1, 1, 1, 1, 1 axis homed" 0 1 I Received=" 000005100, -000002700, 000000200, -000006050, 000007300, 000007000 current position" 0 1 I Received=" 000005100, -000002700, 000000200, -000006050, 000007300, 000007000 target position" 0 1 I Received=" 000000000, 000000000, 000000000, 000000000, 000000000, 000000000 position error" 0 1 I Received=" 00065537, 00065537, 00065537, 00065537, 00065537, 00065537 status word" 0 1 I Received=" 1 lateral link air (0 off, 1 on)" 0 1 : cmd='prim stat' sec stat 0 1 I Received=" 1, 1, 1, 1, 1 axis homed" 0 1 I Received=" 001866500, 001951300, 001853100, 000024950, 000026350 current position" 0 1 I Received=" 001866500, 001951300, 001853100, 000024950, 000026350 target position" 0 1 I Received=" 000000000, 000000000, -000000012, 000000000, 000000000 position error" 0 1 I Received=" 00065537, 00065537, 00065537, 00065537, 00065537 status word" 0 1 : cmd='sec stat' MIG 1 = 1.930500 MIG 2 = 0.557000 MIG 3 = 0.556500 MIG 4 = 0.132000 MIG 5 = 1.907000 MIG 6 = 0.407500 MIG 7 = -6.960000 MIG 8 = -0.347000 Near best focus with imager ( -1800 ) MIG 1 = 1.930500 MIG 2 = 0.558500 MIG 3 = 0.557000 MIG 4 = 1.897000 MIG 5 = 1.907500 MIG 6 = 0.407500 MIG 7 = -5.207000 MIG 8 = 1.387000 Spectro mirror numbers ( in focus ) MIG 1 = 1.930500 MIG 2 = 0.558000 MIG 3 = 0.557000 MIG 4 = 0.081000 MIG 5 = 1.907500 MIG 6 = 0.407500 MIG 7 = -7.023000 MIG 8 = -0.431000 0 0 I PrimCmdMount=5113.,-2701.,188.,-6057.,7319.,7017.; CmdDTime=4.2 0 0 I PrimOrient=0.0, -7.8, 7.8, 427.0, 427.0 0 0 I SecCmdMount=1887163.,1971928.,1905025.,10348.,11798.; CmdDTime=0.4 0 0 I SecOrient=1525.0, 8.4, 25.0, 0.0, -180.2 Dan & Steph