Date: 2021 Apr 18 UTC LBTO Observer: Olga Kuhn (LBTO) Lead Partner Observer: Charlotte Wood (ND) Other Partner Observers: Peter Garnavich (ND), Rick Pogge (OSU, at start) Telescope Operator: Steve Allanson (LBTO) Moon phase: 2d before First Quarter Summary: Started with LUCI in bright moon, then to MODS after moonset, finishing with LBC twilight flats. Seeing good except for between 6:30 and 8:30 when it blew up to 1.5 or worse, then subsarcsec the rest of the night. Transparency was good. 3 LUCI targets ~1.5h each and 2.5h on one MODS target . Calibrations: Twilight sky flats for LBC (ND_BASIC) Completed Observationss: OSU_XMDS_LUCI: SBS1331, SBS1415, HS1442 OSU_ASASSN: Gaia16alq Details (All times UT): ---------------------------------- 01:55 sunset 01:49 The enclosure is open 02:15 Steve is checking pointing and collimating on a star near the first target. 02:47 12-deg twilight OSU_XMDs_LUCI/SBS1331 Telluric HS109615 02:45 Slewing to HD109615 02:57 Starting the spectroscopic observations seeing 0.9-1 arcsec SBS1331 03:00 Slewing to SBS1331 03:06 the beamsplitter cube on DX has not been parked. Steve called Greg and he is moving it as we proceed with the alignment. 03:18 18-deg twilight 03:25 Starting the spectroscopic observations. There was a LUCI1 camwheel error in moving from N3.75 → N1.8. The camera was in the negative limit. Moved it off the neg limit and then commanded N1.8 through the eng gui. Aborted the L2 integration and skipped back to the instrument configuration line to repeat it. It worked fine now. Seeing 0.9-1.1 arcsec 04:30 finished OSU_XMDs_LUCI/SBS1415 04:30 Slewing to SBS1415 04:50 Starting the spectroscopic observations seeing 0.7-0.9 arcsec 05:54 finished Telluric HD127304 05:56 LUCI2 MOS error. The strain gauges needed to be zeroed, and I did that under Dave's direction. 06:03 Sending the acq+obs script for HD127304 again. star brighter than expected, had to defocus OSU_XMDs_LUCI/HS1442 HS1442 06:21 Slewing to HS1442 There is persistence from the telluric - both the spectral traces - in the acquisition images. This target was compact enough to centroid on it. 06:37 Starting the spectroscopic observations. seeing worse, 1.1 arcsec, puffing to 1.5 or worse, settling to 1 arcsec at end, see GCS plot 07:41 finished ------------------------------ 07:41 Reconfiguring for MODS 07:53 Slewing to a pointing star near the target. OSU_ASASSN/Gaia16alq 08:01 acquiring Gaia16alq.acq We made no adjustments based on the through-slit confirmatory images since the object is so extended. It can be seen through the slit in both MODS1 and MODS2. ** NOTE: Acq images were taken with filename 20210417, changed before start of science obs. Merged into 20210418 log 08:18 start science observations seeing 1.4 arcsec 08:30 humidity rose sharply and seeing degraded tp 1.5 arcsec 08:50 humidity back down to ~40% and the seeing to <1-arcsec, got as good as 0.6 during the rest of the observation. 10:32 - Finished Flux Star BD+33 2642 10:32 acquiring bd332642.acq 10:45 observing bd332642.obs - dual grating seeing 0.6-arcsec With such good seeing, the counts in the mods2r spectrum peaked around 48,000 adu in at least one of the spectra from the first set. ------------------------------ 11:11 Reconfiguring to use the LBCs 11:20 Steve is going up to investigate a fault on the swing arm. It was a shear pin fault on the swing arm drive. (IT #8319) 11:28 The arm is in motion now. Blank17+66 for twilight sky flats Slew to field to focus and collimate 11:40 dohybrid 11:59 starting g+i flats at PA=0 scale=5, counts 7000-1000 12:05 repeating g+i flats at PA=0 scale=2.5 12:09 g+i at PA=180, scale=1 12:12 Us+r at PA=180, scale=1 Counts start ~10,000 and go to 24,000. 12:18 Trying Us+r at PA=0, scale=1. Starting ~40,000. ... Dropping scale to 0.5 ...Dropping scale to 0.25 Got a set of Us flats at PA=0 as well as PA=180, but the r flats at PA=0 were a bit high, though some may be acceptable. In summary, we got good flats at two PAs for Us, g and i, and at one PA at least for r. 12:44 sunrise 13:00 taking a series of 25 LBC biases. I had started a set a few minutes earlier but had an LBCR RPC error. I recovered from it and then resent the OB. This set of LBC biases looks pretty good - the LBCR biases do not have horizontal striping, something which was a problem in sets taken earlier this run. 13:10 taking a 2nd set of 25 LBC biases.