Date: Thu, 29 Jul 1999 04:42:48 -0600 From: Dan Long Subject: 3.5m obslog 990728 WEDNESDAY JULY 28, 1999 APACHE POINT OBSERVATORY OBSERVING LOG ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT DATE START FINISH Leeber Leeber GRIM 7/28 20:40 03:10 Turner Long Spicam 7/29 - - INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RS/DN START FINISH D B D B D B USE D B NM02/R 21:40 03:50 - 1.6 - 1.1 - 3.6 0 - 0 PU02/S 04:10 04:40 - 0.6 - 0 - 0 0 - 0 (note: times listed include instrument change time) ACTIVITY LOG (* means a trouble report has been issued or appended to) Observing specialist: Dan Long * During afternoon checkout, I found that Remark would not display GRIM images. Craig traced this to a variable in the mc "hoffset" which was not set properly. He fixed it so it would display. However the bias level values given in Remark were quite different from what iraf would show. For fits images Remark had a bias level of 18000 when iraf showed -2000. For .hhh images Remark showed a bias level of around 50000 when iraf showed it to be about 8000. I opened about half an hour before sunset to allow the telescope to begin cooling. Dawn signed on and wanted to do some cals at about 20:15, so I closed again until about 20:40. I opened again, we proceeded to her field and focused. Problems began a short while later when she couldn't identify her field. I did a pointing correction, but it didn't help. She was still not on her field. After some checking it was found that the altitude was taking up to 30 seconds after each slew to settle into position. I called and talked to Mark. He gave me the needed commands to check servo parameters. A few test sweeps showed velocity out scale varying wildly ( from -700 to -4000 ) from test to test. An inspection of the drive disk showed the disk to be essentially clean except between about 30 and 40 deg where a thick black build-up was seen. An impressive number of moths must have simultaneously sacrificed themselves since the drives were cleaned this afternoon. After several altitude sweeps, I got most of the residue, and generated a consistent velocity out scale of around -580. The altitude behaved nicely after this. I went downstairs to tell Dawn she could continue only to find the mc had hung. Restarting didn't help. It only came up part way. I called Craig and he traced the problem to the fact that the partition of the disk on tycho which the mc runs on had filled. He freed up some space and the mc returned to a working condition. At this point it was a little over an hour past astronomical twilight, so Dawn lost 1.1 hours due to equipment down time. With the exception of some passing clouds, the rest of her run went uninterrupted until 03:10 when I had to close due to humidity. I did not reopen for the rest of the night. OBSERVER COMMENTS FOCUS LOG JULY 28 1999 Wind Time Inst Focus Az El #Temp Dir MPH filter FWHM " 19:45 Opened 20:15 Closed for cals 20:40 Opened 21:50 GRIM f/5 -260(6782) 97 40.1 14.7/17.2 207 7 J 0.93 23:40 Closed due to clouds 00:30 Opened 03:10 Closed due to humidity #First temp is air, second temp is telescope. WEATHER JULY 28 1999 There were thunderstorms in the area in the afternoon. It began breaking up around 17:00, and by an hour before sunset it was looking good enough to open. The skies remained clear to partly cloudy until shortly before midnight when thick cumulus moved in quickly. Half an hour later it moved out just as quickly, back to clear to partly cloudy skies. We were able to remain open until a little after 3:00 when the humidity got too high. It stayed that way for the rest of the night Wind Time Temp F Dewp F MPH Direction Dust Sky 16:01 61 51 8 235 (SW) 793 Mostly Cloudy 17:01 61 51 2 188 (S) 799 Mostly Cloudy 18:01 66 50 2 201 (SSW) 831 Mostly Cloudy 19:01 65 51 8 233 (SW) 733 Partly Cloudy 20:01 60 49 4 195 (SSW) 750 Partly Cloudy 21:01 58 47 8 197 (SSW) 813 Mostly Clear 22:01 57 48 9 208 (SSW) 905 Mostly Clear 23:01 58 48 7 188 (S) 875 Partly Cloudy 00:01 57 48 7 198 (SSW) 715 Cloudy 01:01 56 48 6 201 (SSW) 1023 Clear 02:01 56 48 7 242 (WSW) 948 Mostly Clear 03:01 54 49 7 203 (SSW) 1019 Partly Cloudy 04:01 54 49 3 200 (SSW) 912 Partly Cloudy 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. Dan