From: Russet McMillan Subject: 3.5m Night Log 20030822 Date: Sat, 23 Aug 2003 06:15:41 -0600 (MDT) Apache Point Observatory 3.5m Telescope Night Log Friday, August 22, 2003 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH -------------------------------------------------------------------- B.Gillespie R.McMillan,C.Loomis, SPIcam 21:15 23:00 J.Barentine 01:00 01:15 04:10 05:50 INST SCHEDULED WEATH EQUIP OBS DAY NOTUSED I/RO/DN START FINISH D B D B D B USE D B -------------------------------------------------------------------- EN01/O 20:37 05:36 3.6 2.0 0 0 2.0 1.4 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: R.McMillan Short version: some things still broken, requiring day work to fix. Some on-sky work completed, several nights' worth of on-sky work still to do. After divers difficulties and delays, the telescope was ready to go on the sky tonight. We opened the dome for cooling shortly before sunset, and altitude remaps continued into twilight. Then we discovered that tertiary rotation was broken, and it wasn't something that could be fixed with telephone guidance. After a number of attempts at a solution, we decided we would do everything we could manage working at NA2 alone. Acquiring a star on SPIcam, we found that pointing was distinctly off, but adequate for engineering purposes (we can't get a pointing model with the tertiary facing NA2 because the NA2 guider is down). We also discovered that seeing was extremely poor (around 3 arcsec) and would allow only very rough checks of focus and collimation. We were able to tell that the focus zeropoint has not changed by a large amount compared to pre-shutdown values. We were able to tell that the collimation is extremely poor, presumably because the primary is not yet collimated. We couldn't collimate the primary mirror tonight because the necessary experts were not on-site, but given the extremely poor seeing conditions it could not have been done very well in any case. We next spent a while trying to determine, via unfocused image-donuts on SPIcam, whether the new estimated sag coefficients for the improved secondary mount were roughly correct or not. After about an hour of thought and calculation and attempts to interpret the seeing-blurred donuts, we ended up changing the sag coefficients back to their pre-shutdown values. We concluded that the sag is dominated by effects in the truss and support vanes for the secondary, rather than the secondary flex pivots and center post. Note that this conclusion does not imply that the new secondary mount offers us no benefit; the improvements are expected to include a smaller scatter in the sag (not measurable under tonight's conditions), a reduction in backlash on focus moves (not checked tonight), increased robustness when removing and re-installing the mirror (to be confirmed when the secondary is next removed), and possibly some reduction in sensitivity to windshake (requiring many nights of measurement to assess). We also found that pointing was somewhat improved when the sag numbers were returned to their old values. While we were playing with the sag coefficients, there was a spike in dust and humidity, bringing both right up to the limits and then dropping a little. We kept going until heavy clouds moved in and radar data showed a storm moving into our radar blind spot (or perhaps dissipating -- we couldn't tell, since it's a blind spot). We closed around 2300 MDT and contemplated the data already obtained. Once the precipitation threat had passed, we watched orographic clouds for a while. We fell for a sucker hole shortly after 0100, but were only able to get one image before clouds moved in again. After 0400, a real break in the clouds appeared, so I opened up and had time for an instrument block with SPIcam (almost unchanged from two years ago, despite the rotator rebuild) and another stab at checking the collimation and sag under slightly better seeing conditions. Goals for the next few nights are to fix the tertiary rotation so that we can obtain a pointing model at the echelle, fix the primary collimation, adjust tertiary tip/tilts for the echelle and Shack-Hartmann ports, obtain instrument blocks for GRIM at f/5 (our old one is incorrect) and f/20 (we don't have one at this setting), and use the Shack-Hartmann for a more thorough check of the sag coefficients sometime when the seeing is more reasonable. It's possible this work might be completed over the weekend, but given the unpromising weather forecast, chances are high that we will need to use part or all of Monday night as well. ------- FAILURE LOG ------- PROG INST FAILURE MODE TIME (SEGDFVO) TI/SHU START FINISH DESCRIPTION ----------------------------------------------------------------------- ---------------- FOCUS LOG --------------- Air/Truss Wind Time Instrument Focus Az El Temp-C Dir MPH filt FWHM --------------------------------------------------------------------- 04:18 SPIcam -50(1082) -45 56 12.2/12.4 92 9 i' 1.37 05:14 SPIcam -60(1008) -39 80 11.7/12.2 36 4 i' 1.16 05:43 SPIcam -120(1094) -49 33 11.7/11.9 77 1 i' 1.38 -------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 16:01 66 43 8 116 (ESE) 351 ptly cldy none 17:01 67 42 15 111 (ESE) 316 ptly cldy none 18:01 65 38 10 76 (ENE) 336 ptly cldy none 19:01 63 43 8 93 (E) 438 ptly cldy none 20:01 60 46 17 85 (E) 607 ptly cldy none 21:01 58 46 17 100 (E) 531 ptly cldy none 22:01 56 46 16 91 (E) 1185 ptly cldy none 23:01 54 48 20 83 (E) 1600 mstly cldy dust 00:01 54 46 17 84 (E) 772 ptly cldy none 01:01 54 42 11 87 (E) 364 ptly cldy none 02:01 55 45 8 85 (E) 555 ptly cldy none 03:01 56 44 3 90 (E) 593 ptly cldy none 04:01 54 43 12 80 (E) 388 ptly cldy none 05:01 53 43 8 106 (ESE) 442 ptly cldy none 06:01 53 42 6 92 (E) 374 ptly cldy 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 Primary, secondary, and tertiary mirrors in place and collimated. Primary support system operational. Mirror ventilation system in place. Telescope drives operational. Current Remark version: 2.85b Current guide software version: guider? what guider? Current TCC version: 2.7.1 Current TUI version: TTUI