OSURC Nightlog 20211002 UT Observer*: Olga Kuhn, Ilya Ilyin Lead Partner Observer*: Chrs Howk (ND) Other Partner Observers*: Anusha Pai (OSU) Special Assistants*: none Telescope Operator: David Gonzalez Huerta (LBT) * = from home Plan: The plan is to use PEPSI all night. Summary: Respectable seeing (0.6-1.1”) all night. Likely not perfectly transparent during the whole night. We completed UM_PEPSINV1405 and OSU_BH_Binaries. We also observed ~15 targets from OSU_AbundLowZ. For the latter program we increased the exposure time by an extra 300 sec for ~5 of the targets over what was requested to obtain the desired SNR through weak clouds. Quick Overview: UT0150 – OSU_AbundLowZ – 2MASS J16192696+3507004 [Seeing ~1.0, 1.4"] UT0205 – OSU_AbundLowZ – TYC 3892-429-1 UT0219 – OSU_AbundLowZ – 2MASS J19451462+4929571 [Seeing ~1.4"] UT0238 – OSU_AbundLowZ – 2MASS J19350901+4236426 [Seeing ~1.1"] ** Exposure interrupted at ~7 min mark. ** UT0317 – ** Adding an additional 10 min exposure. ** UT0331 – UM_PEPSINV1405 – 58Aql [Seeing ~0.9"] UT0401 – UM_PEPSINV1405 – V1405 Cas UT0541 – OSU_BH_Binaries – 2MASS J22001521+5559468 UT0700 – OSU_AbundLowZ – 2MASS J00091409+1728209 UT0721 – OSU_AbundLowZ – 2MASS J00021423+3228190 UT0758 – OSU_AbundLowZ – 2MASS J00383315+3433115 UT0815 – OSU_AbundLowZ – 2MASS J01591792+0212080 UT0833 – OSU_AbundLowZ – 2MASS J01051165+3103568 [seeing 0.6"] UT0855 – OSU_AbundLowZ – 2MASS J03004383+0218124s UT0910 – OSU_AbundLowZ – 2MASS J03443498+0553014 [900 sec] UT0922 – OSU_AbundLowZ – 2MASS J04210479+4444455 [900 sec] UT0942 – OSU_AbundLowZ – 2MASS J04315411-0632100 [900 sec] UT1000 – OSU_AbundLowZ – 2MASS J04572322+1338535 [900 sec] UT1020 – OSU_AbundLowZ – 2MASS J05362343+0100444 [900 sec] UT1035 – OSU_BH_Binaries – 2MASS J04123153+6738486 UT1145 – OSU_BH_Binaries – 2MASS J07570459+4300544 UT1220 – OSU_AbundLowZ – 2MASS J05240924+3750376 [past 12 hour twilight] ** Calibrations ** Full Overview (times are given in UT): 0119 [UT] – Dome is open. Clear-looking skies after low clouds cleared out just before sunset. 0124 Opened the PEPSI hatches. David is going to a star near the first target to check pointing and collimate. 01:30 We're collimated. 12-deg twilight is at 01:54 UT 01:36 Presetting to the first target. We may repeat it as it gets darker (plan does not have us starting it until 02 UT) 01:48 Changed binning from 4 to 2. We see some "flux flashing" in guider images (V=12.04). Illya watched guide star flux - at first SX/DX were different but they have converged to the same, giving confidence (aside from the pointing correction on a different target and the fact that this star came right into the guider field of view) that we are on the correct target on both sides. 01:50 Start exposure on first target, 2MASS J1619…+35. With 4 min left, Ilya noted no background sky around the fiber (I did not look earlier to see when it disappeared). 02:00 Changed binning from 2 to 3 as we noticed some fringing on the DX guider images. With bin=3,, this fringing went away. 02:05 Slewing to TYC 3892-429-1. 02:08 Starting exposure. Seeing is about 1.5" SX and 1" DX --- dome seeing? 02:18 Slewing to 2MASS J19451462+4929571 02:22 Starting exposure. Seeing seems to have degraded on DX and is now (02:33) ~1.4" on both sides. 02:37 Slewing to 2MASS J19350901+4236426 02:39 Starting exposure. 02:46 AZ power failed. I stopped the exposure - it was about ½ way through the 15-min exposure. 02:50 Slewed again to the same target to obtain 10 more minutes. The slew is taking a while - we may have problems with the elevation axis now. 03:05 Bruce is going upstairs to restart the TPLC. 02:46-03:15 Downtime due to telescope issues. 03:15 Sending a preset again to J1935…+42 03:17 Starting the 10-min exposure on this source. Avg seeing ~1.15"(SX) and 1" (DX). Chris had an email discussion with the PI regarding the SNR ---- the blue exposures were often not meeting the requested min SNR of 100 and the measurements of all are the most optimistic. 03:28 Slewing to 58 Aql 03:32 Starting exposure. Airmass 1.227. Seeing 1.1 (SX) and 0.8" (DX). 04:00 Slewing to V1405 Cas. 04:05 Starting the exposures. 04:18 Adjusting red side exposure times for V1405 Cas to 7 min – uncomfortably large counts in first image which was 10-min. CD 3 & CD 5 now have 2x15-min (CD3) and 4x7-min (CD5). 04:59 About ⅔ through the first pair of exposures using CD 2 & 4, seeing is 0.87"(SX) and 0.94"(DX). 05:40 Slewing to 2MASS J22001521+5559468 (PI:Thompson). Need to make a pointing check. After that the star came up near the hotspot. The WFS exp time on the left side is 9-sec ! Too low. The spots are too dim for collimation. David manually forced the exptime to 90-sec. A note added to IT 8477 06:50 - we lost the back-reflected star light and see corresponding dims in the guide star flux - wisps of cloud. Clouds are visible on the allsky around the horizon. 06:59 Seeing SX 0.84" DX 0.47" Pointing about 90 deg from the wind - dome seeing? but also I noted that the WFE on SX was 550 nm and it was 75 nm on DX. 07:00 Slewing to 2MASS J00091409+1728209 07:06 Starting the exposure. Blue SNR >~100 and Red SNR ~200. 07:21 Slewing to 2MASS J00021423+3228190 07:24 Starting the exposure. The fluxes (background-sub and scaled by exptime) of the stars are 1.5 times different on SX and DX. For previous targets, these were equivalent. But on the output spectra, the Na line profiles look the same - confirming the same star on both sides. 07:40 Slewing to 2MASS J00383315+3433115. Problem with tip/tilt request for PSF left and right side errors - star not found on left side. On the right side WFS image, the spots are too dim --- exptime is just 9.0 sec! Note added to IT 8477. David is doing a pointing check. 07:40-07:56 Downtime for telescope error. The corrections had built up and on a slew, one of the mirrors hit limits. David cleared corrections, re-entered some initial configuration, checked pointing and recollimated. 07:58 Resent preset and starting the exposure now. Guide star FWHM is ~0.65" on both sides. 08:13 Slewing to 2MASS J01591792+0212080 08:18 Starting the exposure. Guide star FWHM is 0.5/0.57" on SX/DX side. 08:33 Slewing to 2MASS J01051165+3103568 08:37 Starting the exposure. Guide star FWHM 0.58/0.6" on SX/DX side. Some thin bands of cirrus passed through - see the guide star fluxes in LBTplot. PEPSI measures a flux difference on the SX/DX guider, although in LBT plot 08:52 Slewing to 2MASS J03443948+0553014. Problem: WFS image request error, AzCam lost conn? We haven't received a WFS image on the right side since we slewed to this target. Ilay is opening a VNC session to the AzCam computer on DX side - 8w shows no errors but is not moving. Ilya restarted the AzCam Servers for AGw 8("star" icon on AzCam computer) and then David restarted the GCS-R. I sent a preset on the right side only and started the exposure after collimation on both sides had converged. 08:52-09:04 Downtime due to telescope/AzCam issue. 09:06 Started the exposure. Guider FWHM 0.61"/0.68" on SX/DX. 09:21 Slewing to 2MASS J04210479+4444455 09:25 Starting the exposure. Guide star FWHM ~1" on SX/DX and about halfway into the observation, 0.7"/0.9" on SX/DX sides. 09:xx Slewing to 2MASSJ04315411-0632100 09:44 Starting the exposure. Looks like clouds have passed 09:59 Slewing to 2MASS J04572322+1338535 10:01 Starting the exposure. FWHM on guiders is ~1" on both sides.. 10:12 Slewing to 2MASS J05362343+0100444. GCS selected the wrong star on the SX side. Tried to preset again, but again the wrong star - the fainter of the two stars in the FOV and separated by ~10" - was chosen on SX side. David is moving the brighter one to the hotspot on SX. 10:21 Starting exposure. 10:31 Slewing to 2MASS J04123153+6738486 (PI Thompson/Jayasinghe) 10:35 Starting the exposure. FWHM on guiders is 0.80". 11:37 With only 7 min left on the exposure, FWHM on guiders remains ~0.8"/0.7" (SX/DX) 11:45 Slewing to 2MASS J07570459+4300544 (PI Thompson/Jayasinghe) 11:48 Starting the exposure. FWHM on guiders is ~1.2"/1" (SX/DX). 11:18 Slewing to 2MASS J05240924+375036 (back to PI Griffith). No star found (az = -40, el = 82 deg). David will do a pointing check. 11:29 Slewing again to the target. Success. But it is getting pretty bright - sky background is already up to 17.5 mag (LBTplot - sky brightness monitor - white light) at the start of the exposure. 11:32 Starting exposure. We stopped it prematurely (after 7:51 integration time) when the sky brightness reached 15th mag. 13:00 Started the series of calibrations, ThAr and Traces: F200 CDs 1,2,3,4,5,6 F300 CDs 2,3,4,5 13:00 David closed up.