Subject: 3.5m Night Log 20090608 Date: Tue, 9 Jun 2009 12:20:33 +0000 (UTC) From: bketzeba@apo.nmsu.edu Apache Point Observatory 3.5m Telescope Night Log Monday, June 8, 2009 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH ------------------------------------------------------------------- M.Klaene B.Ketzeback Agile --:-- --:-- INST SCHED(TWILIGHT) WEATH EQUIP OBS DAY NOT USED I/ROW/DN START FINISH D B D B D B USE D B ---------------------------------------------------------------------- EN01/W 21:13 04:51 0.1 7.6 0 0 0 0 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: B.Ketzeback Unable to open tonight due to heavy cloud cover and brief rain showers. Much of the first half of the night was spent getting the telescope and instruments back after being powered down today for work on the main UPS. A few of the instruments took multiple tries at reestablishing communications. These included homing the DIS robotics, communications with the echelle motor control and saddle bag temperatures, nicfps and agile ICCs. Second half I powered up the agile rotator and started to take some test flats with Agile through the new filter wheel. The first few sets of flats showed a slight gradient across the field that may have been poor baffling or problems with internal reflections. Switching to the next filter presented a problem. The filter wheel status gave rather strange responses. I'd command the filter wheel to go to position 2 and it would state that it was in position 4 and gave an error code that it had stopped between filters. After about 10 minutes of trying to coax the proper filter in place I headed upstairs. Taking the cover off the filter wheel box I watched the filter wheel as it was being commanded. It was quickly determined that the filter wheel positioning was erratic. Some times it would move 2 or 2 1/2 positions before stopping, other times it would spin 10 times quickly before stopping and loosing its position. Homing the wheel gave nonpredictable results as well more than often stopping near position 4. Comparing to behavior of a wheel in spicam the motor on agile was quite noisy and the wheel detent was not being engaged at all. Three wheels were tried in the filter box for comparison all giving similar results. My conclusion is that the hall sensor in the agile filter box combined with no detent is most likely the problem. After a couple hours of troubleshooting I decided there was not much else that I could do with agile. Finally however I positioned the filter wheel by hand to a known filter position to verify vignetting. There was none. This was a good verification that the gradient that was seen eariler in the evening was from improper alignment of the wheel. Changing filter wheels is not an easy thing to do. Even with the rotator locked at -90 trying to slide the wheel in or out can easily over take the holding torque of the motor and cause it to rotate freely by gravity. This seems dangerous since the obs-spec needs to be a little off balance while holding a wheel with two hands. If the rotator starts to freely rotate there is the potential of dropping a wheel or worse trying to catch your balance and falling into the pit. The obs-specs will need to practice changing wheels safely. I spent the rest of the night working on other projects. The rain sensor went off around 2am. ------- FAILURE LOG ------- PROG INST FAILURE MODE TIME (SEDFNVOG) TI/SHU START FINISH DESCRIPTION ---------------------------------------------------------------------- ---------------- FOCUS LOG --------------- Time Instrument Focus Az El Temp Strc Prim Sec Air filt FWHM -------------------------------------------------------------------------- ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------- 16:00 64 19 13 221 (SW) 939 mstly cldy none 17:00 64 20 20 242 (WSW) 910 mstly cldy none 18:00 61 19 17 253 (WSW) 985 cloudy none 19:00 60 18 20 253 (WSW) 897 cloudy none 20:00 58 17 19 248 (WSW) 818 cloudy none 21:00 58 16 17 261 (W) 682 cloudy none 22:00 57 16 17 248 (WSW) 777 cloudy none 23:00 55 16 17 258 (WSW) 888 cloudy none 00:00 54 17 21 257 (WSW) 793 cloudy none 01:00 54 18 18 265 (W) 754 cloudy none 02:00 52 20 17 267 (W) 771 cloudy rain 03:00 54 19 15 295 (WNW) 927 cloudy lt rain 04:00 53 20 13 274 (W) 1031 cloudy none 05:00 52 20 18 296 (WNW) 965 cloudy none 06:00 54 18 9 272 (W) 984 cloudy 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