From: Russet McMillan Subject: 3.5m Night Log 20000426 Date: Thu, 27 Apr 2000 06:06:16 -0600 (MDT) Wednesday - April 26 2000 APACHE POINT OBSERVATORY Observing Log ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT DATE START FINISH -------------------------------------------------------------------- T.Williams T.Williams DIS-L, 1.5" 4/26-27 18:50 01:00 T.Williams T.Williams DIS-L, 1.5" 4/27 01:00 05:23 INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RS/DN START FINISH D B D B D B USE D B -------------------------------------------------------------------- DD01/S 20:39 01:00 0 - 0.7 - 3.7 - - 0 - NM08/S 01:00 05:23 0 0 0 0.3 1.6 2.5 - 0 0 (note: times listed include instrument change time) -------- ACTIVITY LOG -------- * Means that a problem report has been issued. 1st half Observing Specialist: Camron Hastings We opened at 19:50. The first program took cals throughout the late afternoon. The chips were saturated on DIS at one point and we saw the residual charge in the form of about 15 counts over background in 10 minute exposures. This residual faded away as the night went on. It was too deep into the well for the wipe function to remove it, it just took time. No other instrument trouble reported. The gratings were calibrated and the blue was found to be slightly off, but not by much. DIMM was started up without any trouble and when the sky was dark enough it began seeing measurements. (Sorry Russet) I checked all cable connections and readjusted a few that I thought might be under strain. Whenever the laptop is moved to help aid viewing the screen make sure that no cables are pulled tight. The pointing was not so great tonight. Seeing was though. We found pointing to be off by 40 arcseconds at one point. When I made a pointing correction it was only 10 arcsecs or so. Perhaps we had some bad coordinates, but two different targets were off (in different directions) by a large amount. At around 23:00 the DIMM began showing increasingly poor seeing. It measured u of 2.5 arcsecs while the 3.5-m was measuring 1.0" seeing and this was in the same rough area as DIMM. We were pointed into the North-East at about 56 degrees elevation. The Sloan DSS telescope also measured near 1.0" so there was something going on with the DIMM measurements during this time. * The slit view camera PC crashed twice tonight. The first it crashed while in the 'subframe' mode and the second time it crashed while trying to save an image. * It should be noted that the slit viewer focus is not the same as the DIS focus. It is close, but not the same. If focus is important, put DIS in imaging mode for accurate focus. I will try and rectify this as best I can, but I need a clear engineering night to do so. 2nd half Observing Specialist: McMillan Second half remained clear but somewhat dusty. Closing the louvers and turning on the press fans actually made a noticeable improvement in the dust counts inside the enclosure. After some debate on whether it was more important to have the star focused at the slit so that light wouldn't fall outside of the slit, or to have the spectrum in focus, we compromised by putting the secondary halfway between the best value for the slitviewer and the best for the instrument. Obviously, the long-term solution will be to focus the spectrograph, but this compromise seemed adequate for tonight. Because we were using horizon rotation, most of the time the guider wasn't in use. When we did spot-checks of the seeing on the guider, it was considerably better than the DIMM measurements -- a few times we obtained subarcsecond guider images while DIMM was showing greater than 2 arcseconds. * We had some trouble with the rotator. It overshot one clockwise move by about 30 degrees, then around 04:00 it completely failed to make a counterclockwise move, and apparently got stuck. On inspection, I found nothing binding the rotator or the instrument, and subsequent moves seemed fine, though pointing was rather poor. In the process of making some test moves, I also discovered that * the command track/stop doesn't seem to work. ------------- OBSERVER COMMENTS ------------- FOCUS LOG April 26 2000 Wind Time Inst Focus Az El Temp* Dir MPH filt FWHM" ----------------------------------------------------------------------- 23:10 DIS(Slit) +250(0959) +065 81 14.7/14.7 282 06 none ~1.25" 00:20 DIS(image)+100(0801) +057 62 13.8/13.7 231 10 none 1.34" *First temp is air, second temp is primary. WEATHER April 26 2000 Wind Wind Time Temp F Dewp F MPH Direction Dust Sky Precip. ------------------------------------------------------------------- 17:01 65 19 8 323 (NW) 1283 clear none 18:01 64 18 9 354 (N) 1260 clear none 19:01 65 20 7 276 (W) 1362 clear none 20:01 61 16 1 351 (N) 1481 clear none 21:01 60 17 0 336 (NNW) 1586 clear none 22:01 58 18 3 21 (NNE) 1538 clear none 23:01 61 16 6 268 (W) 1772 clear none 00:01 58 15 6 240 (WSW) 1598 clear none 01:01 59 16 6 235 (SW) 1509 clear none 02:01 56 19 6 180 (S) 1637 clear none 03:01 57 21 8 179 (S) 1738 clear none 04:01 55 25 11 191 (S) 2534 clear none 05:01 55 27 13 187 (S) 2355 clear none 06:01 53 26 12 184 (S) 2616 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 > 1 micron per 0.1 cu. ft. TELESCOPE STATUS ---------------------------------------------------------------- Primary, secondary, and tertiary mirrors in place and collimated. Primary support system operational. Mirror ventilation system in place. Telescope drives operational. Current Remark version: 2.55b5. Current guide software version: GIm Ctrlv3.0b27. Current TCC version is 2.2.5. - Camron Hastings, Russet McMillan