Date: Wed, 14 Jun 2006 07:11:32 -0600 (MDT) From: Jack Dembicky Subject: 3.5m Night Log 20060613 Apache Point Observatory 3.5m Telescope Night Log Tueday, June 13, 2006 ACTUAL ASTRONOMER OBSERVER(S) INSTRUMENT START FINISH -------------------------------------------------------------------- M.Klaene J.Dembicky S-H, DIS 20:00 07:00 INST SCHED(TWILIGHT) WEATH EQUIP OBS DAY NOT USED I/ROW/DN START FINISH D B D B D B USE D B ---------------------------------------------------------------------- EN01/O 21:16 04:51 0 0 0 0 1.3 6.3 0 0 0 note: scheduled times listed include instrument change time ------------- ACTIVITY LOG -------------- Observing Specialist: J.Dembicky Engineering Tasks for 6/13 & 6/14 (result summary in parenthesis): 1) Drive Tuning (looked OK, just did an altitude vel scale adjustment. Russet is going to double check tommorow as well.) 2) DIS grating alignment, calibration, and throughput (Grating is installed correctly, adjustment screws didn't seem to do anything significant, I need to get calibration frames, Russet will do throughput tommorow) 3) NICFPS focus script testing (TBD) 4) Collimation check (TBD) 5) Pointing model (TBD) I first attempted to install IRAF on the Dome Macintosh. I managed to get it partially installed but the path setup is wrong yet (files are in /usr/local/bin instead of /usr/bin). I figured it might be easier to do the DIS grating alignment upstairs instead of running back and forth as I tweaked things and then took images. I then calibrated (even though this probably was going to change as I adjustted the gratings) to center the spectra at 4400A. There was a shift of about -150 steps initially to get the blue spectrum. Initial counts on a 60 sec exposure were around 127 cts @ 4471.48A. For reference the "old" blue medium gratings were 1150 cts @4471.48 with a 30 second exposure. Since nobody on site seemed to have experience in what needed tweaking or how this was a learning experience. I noticed off the Dataq that the rotator motor current looked kind of nasty when rotating in the CCW (negative, 0 to -45 deg) direction vs the CW (positive -45 to +45 deg) direction. This might just have been something to do with the initial roation. I rotatated again in the CCW direction (45 to 0 deg) and things looke a bit better. The alt motor current also looked kind of spikey too but I am not used to looking at those plots . The AZ motor currents looke oscillatory in nature I next checked the velocity scale on the Azimuth drive -613.8772 (+1000 direction) -619.8364 (-1000 direction) --------- -616.8568 ave (-621.0 original value) I did several test slews after changing the value and the data was still noisy and a little spikey (especially downward slews). It looked like there was about a 1.2 sec interval between spikes (and pretty consistent). When there were big spikes they were seen on both the alt and az drives motor currents at the same time. The shack hartman camera somehow turned off when I switched to the instrument and rotated the tertiary (I don't think related). It was working fine up to that point. A lamps off and then lamps on 8 fixed the problem. First test for drive tuning was a star at 89.3 az 40.9 alt. Star seemed pretty stable and seeing was decent. There was a little wander but not much jitter (and jitter was more noticeable when the seeing was about to go bad, so I am not sure if it is a telescope problem). I am not sure about the wander but the star would return after a few seconds to it's original location on its own. I tracked for about 25 mins unguided and the star stayed pretty well placed, so I am not sure what, if anything, to adjust so I left well alone. After about 25 mins the camera started getting more noise and loosing sync. I think it is a cable problem as when I wiggled the cable I could get various amounts of noise to appear (although I couldn't get the noise to go away). I next moved to the S (2 az 82 alt) and there was a little more jitter, although not sure if that was some seeing effect too. I tried at a variety of directions (NSEW) and altitudes and didn't see much jitter in the image. There was a lot of noise on the alt motor current during slews (much more than on the azimuth). Next on the list was the new DIS grating. I tried several various grating zero-steps in hopes that maybe I caught a 2nd order spectrum. Didn't think I did but wanted to exhaust that before I went up to inspect the grating itself. No dice on the orders (I had the 1st order). With the grating installation instructions in hand, and instructions that the Blaze angle MUST point away from the tupe (ie. outward) when in place, I compared the installation instructions picture, which had the blaze direction on the grating holder and then used that as a guide to see which way the grating would be when actually in the beam, sure enough the blaze angle on the picture was incorrect (DIS Blue gratings go upside down compared to DIS red gratings). I spent the next hour taking the graing out and rotating it 180 degrees in the holder, then re-installing it in DIS. I also checked to make sure the grating was square in the holder (well, 2 sides were equal distant on both edges). With the same settings that I found for the incorrect blaze direction grating my first spectra my first spectra gave line counts for 60 second integrations at 4400A of 1000ct, a 10x increase, but only 50% of the intensity compared to the "old" blue gratings. I then looked at how vertical the slit spectra were and saw about a 4 pixel shift from top to bottom (my guess was the grating needs to be rotated). I spent about 2hrs up in the dome trying to figure out what effect the 3 adjustment screws have on the image (I only adjusted the top screw farthest away from the side adjustment screw). I would say that the top two screws should rotate the grating very slightly, whereas the side screw would move the grating linearly (might be used more for centering the grating in the holder and keeping it there. Basically my conclusion of 2 hrs worth of trial and error at adjusting 1 screw (and uninstalling and installing the grating between each adjustment) was that I could see no noticable affect on the images. I move the screw from nominal to CW 3/4 turn back to CCW -1/2 turn (effective range 1-1/4 turn). Images Q2APO/UT060613/dtest.0025b.fits (3/4 turn CW) and Q2APO/UT060613/dtest.0026b.fits (-1/2 turn CCW) are a good example with basically no image shift. (I had the incandescent desk lamp on by my computer during both exposures as well). I re-calibrated the grating (after all the installations/removals) and then started the throughput measurements. When I went up to the dome to open we had cirrus all over now. Russet had logged on so I chatted with her about what might be going on with the gratings and the adjustment screws. She suggested maybe turning on screw CCW and the other CW to get more rotation. I tried this and images dtest.0030b - 35b are the images I got using steps of 1T for both screws in opposite directions (midway I went reversed). The last image was with the grating again re-aligned in the holder against the edges (which is how I left it). I didn't see much change in the images. I left DIS mounted in case anybody on the day staff wanted a stab at figuring out what was going on with the gratings, Plus Russet will need DIS for the throughput measurements tommorow. DIS can be unmounted if necessary during the day. ------- FAILURE LOG ------- PROG INST FAILURE MODE TIME (SEDFNVOG) TI/SHU START FINISH DESCRIPTION ----------------------------------------------------------------------- ---------------- FOCUS LOG --------------- Air/Truss Wind Time Instrument Focus Az El Temp-C Dir MPH filt FWHM --------------------------------------------------------------------- ------------- WEATHER LOG ---------------- Wind Precip.or Time Temp F Dewp F MPH Direction Dust Sky Conditions ------------------------------------------------------------------ 18:01 74 30 2 204 (SSW) 985 Pt. Cldy none 19:01 76 33 7 254 (WSW) 1032 Pt. Cldy none 20:01 71 28 9 219 (SW) 1017 Mst. Clr none 21:01 69 28 13 170 (S) 1091 Clear none 22:01 68 27 19 152 (SSE) 1218 Clear none 23:01 66 28 25 142 (SE) 1540 Clear none 00:01 64 31 24 144 (SE) 1360 Clear none 01:01 63 33 21 142 (SE) 1306 Clear none 02:01 63 34 24 141 (SE) 1432 Clear none 03:01 64 28 18 163 (SSE) 1290 Cirrus none 04:01 64 27 18 180 (S) 1226 Cirrus none 05:01 64 27 17 186 (S) 1151 Cirrus none 06:01 64 28 14 199 (SSW) 1176 Cirrus 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: 2.8.4 Current TUI version: TUI 1.2