Date: Fri, 8 Oct 1999 07:24:23 -0600 From: Dan Long Subject: 2.5m obslog 991007 ( MJD 51459 ) THURSDAY OCTOBER 7, 1999 APACHE POINT OBSERVATORY SDSS 2.5m OBSERVING LOG Observering team: Dan Long (APO) Steph Snedden (APO) Connie Rockosi (UC) Tonight's plan was to obtain imaging data on the equatorial stripe 100 N starting at RA 20:40 and also to get some engineering data tracking slowly using a stripe nearby to the equator and meridian ( stripe 11 ). Stripe 76 was also a candidate for a science run. Should the conditions not be photometric three cartridges were plugged and ready to go for spectroscopy Cartridge Current Plate 2 192 22:30 4 212 03:30 5 197 23:30 In short the weather tonight prevented us from doing what we would have preferred. Clouds kept us closed until ~21:00. It was clear the rest of the night, but with high winds and poor seeing. We did imaging of 100, N starting at RA of 20:40. The scan ran a couple hours but the seeing wouldn't settle down, so we switched to an engineering scan ( stripe 11 ) which to test the telescope's ability to track slowly. The seeing began to improve after about an hour of this scan, so we decided to try a stripe in the survey area ( 76 ). The seeing promptly got worse, and the wind picked up almost to the point where we would have to close. It was now too windy to change instruments, so we let the scan continue. At about 04:30 we went out of the survey area on 76, and decided to do a FASST field as the wind was still gusting over 30 MPH and it was really too late to set up for spectroscopy. Run 1007: Bias run Run 1008: Set up for 100,N Run 1009: About 2.5 hour scan of 100,N starting about 20:40 RA. Seeing occasionally teased by going to 1.5" but was generally around 2". Run 1010: Stripe 11,N lambda -173 For about an hour seeing 1.4 - 2.2" Run 1011: Stripe 76,N lambda 170 For about 2 hrs, seeing 1.5 - 2.5" Run 1012: Setup for FASTT field Run 1013: FASTT field D. Seeing 1.6 - 2.5". We saw some odd behavior with findRotator. First, if you use -nmax it can generate poor results with large errors. Using a sigma higher than the default on the same data to get a similar number of points as the desired nmax, calculates rotator changes with much lower errors. However tonight on run 1008 it seemed to be over-estimating changes. Either that or offset rotator was over-doing the changes. Each time we made a change and checked with another lskip, it would ask for a correction in the opposite direction of about 1/3 of the previous correction Like last night DIMM was reporting much better image quality than the 2.5m was getting. DIMM was saying 1.0 arcsecond fwhm at Polaris while the 2.5m was at considerably higher elevation and getting 2+ arcsecond fwhm. All indications are that DIMM is being far too optimistic in its seeing estimates. Even stars overhead were twinkling at times, and when looking at the DIMM images, one could see them dancing all over. I'm beginning to wonder if DIMM isn't measuring the differential motion of a pair of dead moths. We had trouble running skyGang again tonight. We got further this time. We could get it to plot the observed and catalog stars, but when we went to make a match ( the "b" key ), it would bomb out saying astrom> skyGang 1009 170 180 5 -node 95.0 -incl 0 -useHdr 0 -ha 1.81 -dec .10483 Open /XWIN Cursor: o-observed (green), c-catalog (yellow), b-boresight, q-quit Error: Syntax Error: expected 2 more required positional parameters USAGE: astStarPlaceRefr -help This happened for both the parked and powered stripes. A problem report has been issued. MIRROR NUMBERS Primary: setmir: 0 -27.4 7.8 427 1495 galil: 6400, -3350, -450, 11050, 7350, 7050 linear gauges 1 = 1.9265 2 = 0.5600 3 = 0.5585 5 = 1.9065 6 = 0.4065 4 = 4.5180 7 = 4.5565 8 = 4.7330 Secondary: ( inst=imager focus=-1411 alt=55.0 deg ) setmir: -157 -111.5 45 0 205.5 galil: -383213, -230636, 20596, -13521, -10768 TPM data was logged for most of the night in "/mcptpm/tpm-51459". The imager is on the telescope. The telescope was closed up at around 06:00. Like the last couple nights, the primary went into oscillation during the stow process. It was backed off to the reverse limits. Nitrogen notes: Both spectrographs were filled at 18:30, and at about 06:15. The imager dewar was changed at about 19:00. EndNight -doImager for MJD 51459 was started. WEATHER Skies tonight were cloudy between 19:30 and 21:00. It was clear after 21:15. The temperature started around 50 and dropped into the upper 30s by morning. Winds were from the north at 20 to 35 MPH, humidity was around 50%, and dust counts were under 1000. Seeing tonight was between 1.5 and 3.0 arcseconds on the imager, but around 1.0 arcseconds on DIMM. A moth was found in the dewpoint sensor during the day and was likely the cause of yesterday's flaky behavior. Dan