Date: 2021 Jan 05 UTC LBTO Observer: Olga Kuhn Observers: Mark Whittle (UVa), Rick Pogge (OSU) Remote Participants: Kyle Corcoran (UVa) Atharva Gorantiwar (UM) TO: Steve Allanson Special Assistant: Trim All observing is remote in C-19 mode. Moon phase: Waning gibbous, 62% illuminated, so bright-ish time after ~0615UT Twilight at ~0150UT evening, 1250UT morning Summary: Getting into gray time, so started with MODS, shifted to LBC. Seeing mostly >1-arcsec, up to 2+arcsec but episodes of subarcsecond and always variable. Clear at twilight but cirrus and started coming throug at 4UT and stayed through to dawn with varying degrees of severity from nuisance to ~1 mag. Moonlight raised background later with the cirrus around. Instruments: LUCI1+2, MODS1 R+B, MODS2 B, LBC Red Unavailable: MODS2 Red (suspected dewar leak), LBC Blue (rotator failed) Calibrations: Too cirrusy for sky calibrations, did LBC-R biases and LUCI darks. MODS flux cals: G191b2b and GD71 (through cirrus) Executed Programs: MODS: OSU_Lithium BrownDwarf6 UVa_WISE J0342 UM_Dwarfs HS0837 (compromised seeing/cirrus) LBC-R: OSU_monitor, I-band program (N2403,N3077,M81,M82,I2574) regular: I2574, M82, (N2903 attempted by prob. compromised) Time Lost: Some time lost to heavy cirrus no guide stars, some time (~1-2h) will be effectively lost as highly variable seeing during visit compromised data even though start was in acceptable seeing. Details (All times UT): ---------------------------------- Instrument: MODS1R+B/MODS2R 00:55 Opened enclosure, configured for MODS 01:00 pointing and collimation, waiting on seeing to settle OSU_Lithium - BrownDwarf6 Because this is red-only we are just using MODS1R, MODS2 idle 01:26 started acquisition at 12-degree twilight and letting WFS settle on the approach to 18-degree twilight at 01:55. Seeing ~0.8-1" Using a special masked acquisition script, so takes a little longer. Needed because of a very bright star that would bleed into the dispersion direction of the brown dwarf. ACQ is in sdss_z so not bothered by being ahead of 18-degree twilight 01:44 started science observing ~10 minutes before 18-degree twilight again noting very red spectrum (>7000A). Exptime for visit is ~2h First image shows stray light with a blue spectrum. Examination of the wider field (out to 2-degrees) shows a bright A5III star (Beta Tri, V=3) 118-arcmin away. Stars like this are known to cause bright "arcs" in the focal plane because of the undersized secondary mirror (starlight goes directly into the direct gregorian hole in the primary). Rarely see it this dramatic in spectra. Going to see if it changes between images. Seeing variable 0.8 down to 0.6, the Background does change with image, as expected given rotation through meridian (also see in acq images, etc. historically, nothing new here, just unlucky). 03:22 - seeing puffing up to 1-1.2" during the last of the 1800s exposures. Note: examination of spectra with quick-look gives no flux <7800A. We looked up the star in Simbad and it is type T3, which has no flux below that. Not great for looking for the Li 6707A doublet. Note other stars in this program were L-dwarfs where that is not an issue. Will communicate the quick-look data to the PI. 03:54 - Flux star G191B2B MODS1 dual and red-only, MODS2 blue-only grating UVa_WISE J0342 04:38 Going to UVa_WISE J0342. Two objects on slit, AGN and nearby galaxy of unknown redshift, separated by 12-arcsec. Will acquire to position the CCD quadrant boundary between the two. Increases ACQ overhead 05:00 Start of observations original script is 5x300s, but we had to use 120s exposures to see in acq. Cirrus affecting images (all-sky and guide star) 05:17 Stopped script after 2x300s, increased to 3x1200s, got lots of signal, but were clearly in cirrus. Seeing ~1" but puffs to 2" in last exposure sequence. AGN clearly detected and rich in lines, other galaxy has a single emission line, helpful/not-helpful, maybe reduction will give some absorption to help ID and get redshift. UVa_WISE J0612 [failed] 06:23 Slew and acquire, also 2 objects ~12" apart, similar acq process Seeing ~1.7" now, puffs to 2" Could not see objects in slit after acquisition, seeing and cirrus clobbering us, abandoning 06:47 Flux Calibration Star GD71 MODS1 dual and red-only, MODS2 blue-only UM_Dwarfs HS0837 07:30 Slew and acquire HS0837. Was outside the nominal +/-10min tolerance for parallactic, so tweaked script before visit to advance the mid-visit PA by the required amount. Seeing 1.5-2", so starting out a bit beyond the requested <1.1" seeing 07:47 Started science exposures (3x1200s), 1.5-1.7" seeing 08:54 Seeing 1.3" at end. Record of guide star count telemetry showed a lot of cirrus and highly variable seeing. Can see emission lines including the targeted auroral lines, but moon is up so high background and some solar absorption in sky (CaII H&K, H-alpha). Will have PI check, but probably compromised by changing conditions. ------------ Reconfigure for LBC-R 08:55 - reconfigured for LBC-R (left MODS1 in beam) OSU_monitor - I program 09:07 N2403, 1.1" seeing, cirrus getting heavier 09:27 N3077, 2" seeing, cirrus cleared some at end 09:45 M81 - seeing 1.7-1.6 arcsec, cirrus better but present 10:00 M82 - seeing 1.4", cirrus 10:15 I2574 - seeing 0.8-1", lighter cirrus OSU_Monitor - regular program (red only because no LBC-B) 10:34 I2574, back to focus field, then start R band series in LBC-R seeing ~1", a little cirrus on all-sky camera (bands) 10:54 N3627 - started but too close to the moon with cirrus during focus abandoned 11:03 M82, seeing 0.7-0.8", better than before! Back to moonlit cirrus 11:20 N2903, start with I then R, but had problems with large z11 corrections during focus setup (temperature changes during the night). First I image background saturated, bands of moon-illuminated cirrus rolling through and getting thicker. Abandoned. 11:46-12:11 - Stopped observing due to heavy cirrus lit by moon 12:12 - Back go N2903, R. Better now, seeing 0.6-0.8" 12:37 - seeing some IQ degradation towards the last exposues, guide star comatic. FWHM 1.6" 12:55 - 18-DEGREE TWILIGHT 12:58 - Done, but going back to the focus field to recollimate 13:00 - back to focus field, got FPIA convergence, seeing ~1" 13:24 - 12-DEGREE TWILIGHT 13:29 - background getting too high due to twilight, moon, cirrus seeing ~0.8" --------------------- Closed-Dome Calibrations MODS: MODS1 red-only and repeat MODS2 blue-only pixflats (more light) LBC: LBC-R biases x 25 LUCI: ND_j0053ir Dars