Date: 2021 Feb 10 UTC LBTO Observer: Olga Kuhn Lead Partner Observer: Hayley Williams (Minnesota) Other Partner Observers: Rick Pogge, Chris Kochanek (OSU) Telescope Operator: Steve Allanson Moon phase: Waning Crescent Summary: All MODS tonight. Clouds at the start, then an opening about 3.5h after sunset, then started ~0400UT with a standard (G191-B2B) and an OSU_ASASSN target acquired in subarcsec seeing and some thin clouds. After 0600 clouds became worse, and during subsequent target clouds were a serious issue, many magnitudes of extinction and guide star loss. All data taken oafter 0600UT were compromised by clouds. PI review of data requested to determine which need do-overs. Calibrations: All MODS calibrations completed while the clouds kept us closed. Also did LUCI darks at the end of the night for upcoming LUCI programs. Details (All times UT): ---------------------------------- 01:04 Sunset 01:26 remaining closed due to clouds and virga. Doing MODS cals while the dome is closed 03:39 Clouds passing around us, OK to open up 03:47 Steve is correcting pointing and collimating near the first target. 03:54 G191-B2B Dual Grating standard star Seeing/FWHM of the guide stars was 0.8" on average 04:18 OSU_ASASSN/ASASSN18vc Using the UT6 acquisition as closest in parallactic. Target is very faint, so very 04:44 started science exposures, seeing 0.7-arcsec 05:24 Seeing still <~0.7" on average. 05:52 Done: ransparency was pretty stable and good throughout and seeing, too, ~0.7". 05:52 OSU_CLASSY/J0808 dual grating 06:08 execBinoMODS J0808.obs 06:15 At the start of this observation, the seeing is 0.55"! However, the transparency is getting bad, seeing peak-to-valley changes in guide star flux of ~1.5mag on LBTPlot. 06:29 very short bursts of seeing ~1.5-1.7" Data probably compromised, PI should review 07:17 OSU_EELGs/J0944 07:23 It was a long slew and the guide star was not in the acq field for MODS1 (pointing offset, not bad guide star). Resent the acquisition. 07:34 Science script start 07:35 At the start of the exposures, the avg FWHM on guiders is 0.9-1" and the clouds seem to have moved away - the guide signal is improving 07:44 No, I wrote too soon about the clouds. The guide signal is down by 2 mags from the peak value it attained earlier. 07:57 Guide star flux is coming back 08:15 But, now the clouds are coming back and ... 08:20 guide star flux drops, then recovered by start of next exposure 08:36 Again close to losing the guide star. 08:41 guide star highly variable, up to 3.5m of extinction, during 3rd exposure of 3. After the observation of J0944 completed, the clouds were too thick to consider going right away to the next target. We're paused for clouds. 08:49 Steve is closing as the clouds are only increasing right now. 08:57 Resuming MODS calibrations while the clouds are around, starting with MODS 1" dual grating slit flats and LUCI darks. I'll add the image numbers to the table above. All of the unbinned MODS calibrations have been done. 10:13 Steve is reopening. There are still clouds passing through, but they are not threatening. 10:21 OSU_EELGs/J1148 Seeing is ~0.7" during the acquisition Clouds with 4 mags of extinction wiped out the confirmatory thru-slit images. 10:39 Taking a second set of confirmatory images when the guide star has some flux. 10:49 started science observing. The guide star flux is about as high as it's been. 10:56 Already, the guide star flux has dropped and it's barely hanging on to the guide star. Came back. Lines seen in first spectra. 11:17 Barely holding onto the guide star - about 5 minutes into the 2nd observation. 11:57 The series of exposures is done. It's not clear how much if any is useful since the transmission was highly variable and at times the star nearly dropped out. 12:05 HZ44 dual grating Steve is checking/correcting pointing. First set of images is weak and soon after we lost the guide star. 12:25 execBinoMODS hz44.obs for the dual grating spectra. The guide star is disappearing and it looks like the clouds are closing in during this observation. 12:31 No longer guiding. We'll abort the script after the 2nd set of exposures - these do not even show a trace. 12:35 Steve is closing up.