Date: Sat, 1 Nov 2008 07:00:03 -0600 From: "Jeff Coughlin" Subject: 3.5m Night Log 20081031 Apache Point Observatory 3.5m Telescope Night Log Friday, October 31, 2008 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH -------------------------------------------------------------------- H.Chen H.Chen DIS 17:00 00:55 O.Fox O.Fox TSPEC --:-- --:-- INST SCHED(TWILIGHT) WEATH EQUIP OBS DAY NOT USED I/ROW/DN START FINISH D B D B D B USE D B -------------------------------------------------------------------- UC01/R 19:07 01:00 0.8 0 0 0 4.3 0.8 0 0 0 UV06/R 01:00 06:27 0 0 5.5 0 0 0 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: J. Coughlin Az Velocity Scale was 588.0, measured 584.3, 588.8; 586.5. Changed to 586.0. We were able to open on time, although uniform clouds persisted through sunset, and slowly thickened until 20:45 when they finally thinned out. First half observers were able to get a reference star after opening, but could not find thier faint objects from 20:00 to 20:45 and thus I've marked that as lost time due to weather. At about 23:55, the dcam started displaying values of 25k across the chip (see image #350-353), while guiding on 30 second exposures. There were no clouds, no lights on in the dome, and nothing issued by myself or the observers between images #349 and #350. I stopped guiding, and took a 5 second exposure (#354) which showed a double image as if the telescope had jumped in tracking. I took another 5 second image which appeared to be normal, #355, and then a 30 second which was also normal, and we were able to resume guiding. Problem seemed to fix itself, and did not re-occur tonight, but still unsettling and I have no idea as to the cause. Observers were able to continue thier DIS exposure during the guider glitch and thus I did not count this as equipment down time. Tspec took me a few extra minutes to get mounted, but it was ready by 01:23. I did not fill it this afternoon since it was to be used tonight - will fill in morning. At 01:30 the observer commanded a slew to his first target, but there was an error on the rotator, I believe motor limit (the exact message has dissapeared from the logs.) Since this happened I belive last time tspec was on, I tried dismounting then remounting tspec in case it wasn't balanced right. I then did a slew through the TUI window using the same alt az coords as the telescope was currently on, but moved the rotator 5 degrees, and it slewed without problem and I confirmed visually it moved properly to +5. I then did a tcc rot 0 mount and it moved back to 0 without incident, so the rot error appeared fixed. I then went back downstairs and told the observer to go ahead and slew back to his field, which we should have still been very close to. The telescope slewed, but we then noticed that there was a "Motor 1 Currnet Limit" error in the status window. We were at an az of about -69 deg. The observer could not see any stars in his field, and so I tried slewing away by a few degrees in alt and az. Alt moved fine, but Az did not move and gave the same error. I then halted axes and hit a stop button, and checked for a dome collision, but there was no collision. I tried re-initing the axes, but the motor 1 current limit error persisted. I then called Russet, and she had me run an Az velocity scale. In the positive direction, it gave a value of 589.6, but in the negative az it gave a ridiculous value of 4520.9. The Tach values seemed to behave normally with a ramp up\down trapezoidal feature, but seeemed noisy after the negative az run finished. At this point I called Nick, and he had me run a few small slews, and watch the tach. Got "acceleration limited" error for very small slews of a couple tenths of a degree, and "motor 1 current limit" for slews of 2-3 degrees. At this point Nick came up to the site and assesed and we told the observer we'd be down for the night. We rebalanced the telscope and did an az remap. I then ran an az velocity scale and got 589.4, 592.9, 591.2, and updated. With Russet we then ran a quick pointing model up until just before sunrise. Hopefully this can be analyzed during the afternoon tomorrow and if good we can be back on schedule for 1st half observing tomorrow night, but it is not a certainity. ------- FAILURE LOG ------- PROG INST FAILURE MODE TIME (SEDFNVOG) TI/SHU START FINISH DESCRIPTION ---------------------------------------------------------------------- UV06 Tspec T/H 01:00 06:27 AZ Drive Imbalance - See Above ---------------- FOCUS LOG --------------- Time Instrument Focus Az El Temp Strc Prim Sec Air filt FWHM ----------------------------------------------------------------- 18:50 dis-slit 15( 244) 27 54 10.0 12.5 11.3 11.2 10.5 1.5 1.00 19:21 dis-slit 45( 204) 14 57 9.7 11.2 10.7 10.1 10.0 1.3 1.00 ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------- 16:00 55 31 5 259 (W) 1103 ptly cldy none 17:00 53 32 1 254 (WSW) 1112 ptly cldy none 18:00 52 28 2 187 (S) 1034 mstly cldy none 19:00 50 25 10 172 (S) 1142 ptly cldy none 20:00 50 23 12 156 (SSE) 1036 mstly clr none 21:00 49 23 8 172 (S) 1098 clear none 22:00 50 22 7 158 (SSE) 1008 clear none 23:00 49 22 7 180 (S) 1105 clear none 00:00 49 22 3 182 (S) 989 clear none 01:00 49 22 2 152 (SSE) 1020 clear none 02:00 50 20 1 173 (S) 911 clear none 03:00 49 21 2 187 (S) 972 clear none 04:00 50 22 1 153 (SSE) 1025 clear none 05:00 50 21 1 145 (SE) 1070 clear none 06:00 49 22 1 176 (S) 1130 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 > 1u per 0.1 cubic feet. TELESCOPE STATUS Telescope drives operational. Current TCC version: 2.9.1 Current TUI version: TUI 1.5.1