Observers: Pogge, Villanueva Telescope Operator: David Gonzalez-Huerta Support Astronomer: Olga Kuhn Instrument: LBC and MODS1 Observing Log for 2013 Mar 18/19 Summary: Mostly clear but clouds threatening from the west later tonight. Light winds. LUCI1 is down with mask grabber issues, so we'll run another split LBC/MODS1 night. Cirrus came in before sunset and stayed with us through the night. At a few points it became overcast and we could not acquire guide stars or collimate with MODS, hastening an early shutdown around 5am after which unable to catch photons from space we made our own photons and did internal calibrations until dawn. Seeing was 1", with a few episodes of 0.6-0.7-arcsec seeing under 0.5 to 1 mag of cirrus. We had to supplement some exposures to reach S/N targets given in-and-out cloud bands. Given gray time, we had to watch moon-angle, and had high backgrounds on all targets because of moon and cirrus until moonset later in the night. The better seeing than last night made up for the problems. Details: All times are UTC unless otherwise noted 23:00 - Hand-over, doing dark-dome/zenith-pointing calibs for LBC and MODS1 MODS1: sieveSnap, grpixflats, grlamps, OSU_CLASH/a1423.cal slitflats_Mar13.cal, LBC: 25Bias_Bino, 2Darks_Bino 00:30 - cirrus incoming, winds still calm 01:45 - LBC Sky Flats BR and VR 02:20 - Going to a collimation field (first target still too low) RA=05 Dec=+10 (El=55). Not quite enough bright stars, second field at RA=07 Dec=+10. OSU_monitor/N3344 02:50 - acquiring focus/collimation field 03:00 - Strange readout artifacts on red, blue is OK. Power cycling cameras to try to clear this condition. 03:16 - Science Observing - seeing ~1" on the guiders. Definitely cirrus and moonlight (V=21mag/sq-arcsec clear-sky). Under way and guiding... First images: 0.9-1.1 arcsec (red-blue). Blue a little elongated. Sky background is pretty high, 20-30K ADU (moon & cirrus) Blue image quality is not as good as it could be. Red background getting to 40K ADU because of cirrus OSU_monitor/N3489 03:48 - Acquiring focus/collimation - looks better (less Z22 on blue) Seeing ~1-arcsec on co-pointing. However, blue is slightly off, adding +500nm of Z4 and taking another image. 03:59 - Science Observing - bands of cirrus lit up by the moon blowing over us, going to play hell with the background. Seeing is a little under 1". Background in red 10-15K ADU Blue images have quality issues. Not much we can do. 04:34 - Had to stop and refocus blue, it slipped steadily out of focus. Red, by contrast, was rock solid. Running dofpia on the target field as the analysis portion is far enough from the galaxy. Definitely seeing a lot of Z11 (3rd order spherical), and a little bit of coma in blue. 04:42 - Running the no-U version to try to get better blue imaging quality. First images show improvement, but will it hold??? Less cloud about half way through the OB, with subsequent drop in the background (7K ADU). OSU_monitor/N2403 05:20 - Focus and collimation field. Converged fast and clean. Seeing ~1 arcsec. Blue images much better. Oddly red is a little softer than blue this time. 05:30 - Executing science OB. Red bkgd ~10K ADU. 0.8-0.9 arcsec, now blue is softer by 0.1 - go figure. OSU_monitor/M101 05:40 - Focus and Collimation field. Seeing a little softer, 1.1-1.2 arcsec, also seen in the DIMM. 05:50 - Executing science OB. First images, red 15K ADU background, ~1 arcsec Definitely more clouds than during NGC2403. Blue images a little elongated, but not as bad as before. --------------------- 06:20 - Reconfiguring to MODS1 Clouds approaching from west, not sure how long hole will last. 06:40 - Finished, going to pointing star & initial collimation star 06:50 - Collimated, seeing 0.9 arcsec (as low as 0.8 at times) OSU_GREY/Mrk1450 - HII target 06:51 - Acquiring. We're in a cloud hole, virtue of this gray-time target is it is a) bright, b) a short (30min) visit, so we won't run out of time before the next cloud band hits us. Seeing 0.9-1", but cirrus (see background in WFS shack spots). 07:00 - Executing spectral observation. Seeing a little less than 1-arcsec. 3x400s to start. Will assess impact of clouds to see if we need any supplementary exposures. First spectrum looks good, lots of emission lines. Background is coming up as cirrus comes over - pretty much covers the sky. Seeing ~0.9". Second spectrum cirrus moved in, attenuating guide signal by about 1.5 mag. Can see bkg coming up. Same during #3 07:28 - Started another 3x400s since we're getting cirrus absorption. (lost the DIMM during exposure 1). Came back quite a bit during exposure 3, but still mostly overcast. Seeing 0.8-0.9 arcsec. *** Overcast cirrus but thinning a little *** GD153 - Standard Star 07:55 - Acquiring star. Guide star clobbered by clouds, losing it. (R=14.2) going to Feige 66, which has an R=12.4 mag guide star. Feige 66 - Standard Star 08:00 - Acquiring target. R=12.4 for guide star, can guide and get WFS correction. Seeing 0.7 arcsec - clouds begone!! 08:07 - guide star lost in clouds. waiting for its return... 08:10 - taking spectra (dual grating) - guide star recovered from clouds. We'll see how long it lasts... Wind is coming up. 08:18 - lost guide star again 08:24 - came back, got last grating spectrum, firing dual prism script. OSU_PC/qso1145m1 ** modified .acq script to use a brighter guide star (R=13.9 instead of R=15.7) because of cirrus. no blocked slits 08:37 - no stars, closing for now. 09:06 - stars! We're opening up... ------------- 09:25 - We're closed for a while, doing calibrations. OSU_PC/qso1145m1.cal 09:42 - aborted - we can open again for a little more... ------------- 09:58 - acquiring qso1145m1... Seeing is around 1", but a little jumpier than previously tonight. Good centering, ~1 pix +y vertical, but that's within spec 10:10 - Starting science script. Seeing 0.9-1", but sometimes we get a puff to 1.2 that settles back down. Cirrus present, the AGw photometry trace shows about 0.5mag of up and down modulation in the total brightness of the guide star. 10:47 - Running another 2x900s +/-1 offset run (m1_extra.obs) since we've seen the guide signal recover during the second compared to the first. Maybe you'll get lucky. The first was with a guide signal comparable to spectrum 2 of the first set. After that the guide signal declined nearly a full magnitude part way through. Make a difference image of #2 and #3, we detect at least 6 continuum objects, so there is info in the spectra despite the challenging conditions. 11:14 - lost guide star, stopped #4 at 630 of 900s completed. ---------------------- 11:16 - clouds getting heavy. We're closing, running the scope to zenith and resuming calibrations, starting with a do-over on the qso1145m1.cal script. 11:23 - qso1145m1.cal - didn't note until late that it was taking 5 each of the comp lamps where 1 is needed. We stopped this late when we noticed it seemed to be taking an excessive time to execute. 12:05 - prflats, prlamps, and prbias.cal to finish out the night ----------------------