Date: 2021 Feb 11 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/New Moon

Summary:

MODS again tonight. Lost a little over 2 hours at the start due to ash
and smoke from forest service controlled burns in the Gailuros
mountains near the old YLE ranch.  This is upwind of Mt. Graham and we
had ashfall outside and strong smell of smoke in te=he building.  A
few clouds but clear by 8UT and stayed mostly clear all night.  Seeing
subarcsecond with episodes up to 1"+


Observed MODS programs:
  ASASSN20qj, 
  ND_SN04am, 
  OSU_EELGs: J1148 (redo because it was clobbered by cloud last night) & J1323
  OSU_XMDs_MODS/UM461
and the standards, GD71 and Feige66 in dual grating mode.


Calibrations: 

LBC sky flats and biases at dawn.



Details (All times UT):
----------------------------------

01:05 Sunset

02:24 18-deg twilight

02:26 We remain closed due to smoke/ash.

04:11 Steve is opening up the chamber

04:19 Going to correct pointing and collimate near the first target.

04:27 Standard star GD71 dual grating

04:35 spectra start.  FWHM on guiders is ~1/0.7" There is some dome
      seeing. Sky looks clear overhead but not photometric. There are
      some clouds on the horizon, primarily on the ESE and NW.


04:54 OSU_ASASSN ASASSN20qj

05:11 science start

05:15 The FWHM on the guiders are 0.66/0.6" - a little larger on SX
      than DX, probably some dome seeing. The SX/DX discrepancy was
      greater on the first field.


05:48 The guide signal is holding steady. No clouds over the target,
      but some clouds on the allsky camera


06:08 With about 500 sec left on the 3rd exposure, a cloud came over
      the field and the guide star flux dropped by 4 mags, then 2
      more. It recovered a bit but never fully.


06:20 ND_SN04am slew and acquire.

06:42 science start. Pause due to imcslock timeout (elevation).  Guide
      signal has been pretty steady - clear in the direction of the
      field.

07:13 The average seeing is about 1.1" on the guiders, up from <~ 1"
      seeing at the start.


07:51 OSU_EELGs J1148

      The seeing is ~1.1" and it is pretty clear in this direction,
      although there are still clouds on the horizon.

08:05 science start


08:15 Clouds are closing in… the guide star flux just started to dip,
      but it recovered at 08:27, around or before the start of the 2nd
      exposure. The second exposure was taken in pretty clear
      conditions and the 3rd is starting well.

08:51 Seeing is back down to ~0.65". 


09:14 OSU_XMDs_MODS UM461

      Guide star is a double. There is another star, R=16.77 and
      B=14.81, a bit fainter than the limits, but it is all there is
      and the seeing is very good.


09:22 acqBinoMODS UM461_UT0930_newgs.acq
      This guide star is fine - robust counts. 
 
09:37 science start

      The seeing at the start is ~0.9" and the guide signal looks
      good. Very little or no cloud at this pointing.


10:45 OSU_EELGs J1323

11:00 science start



12:10 Flux Standard Feige66

12:20 spectrum start, airmass 1.114

12:45 Reconfiguring to the LBCs for twilight sky flats Need Us, B,
      V + R, F972N20

13:11 It's early - dofpia so we don't have to mask out donuts.

LBC sky flats
B +R at PA=0 and PA=80
V + R at PA=180 --- counts are high at V
Us + F at PA=180 ---  of 5, 3 Us are good and all 5 F9, got 1-2 more Us flats with 0.3-sec exptime.
Us + F at PA=0 --- for F - no, we saturated.

13:57 Steve is closing up.

Closed Dome Calibrations

14:09 Running a set of 25 LBC biases. The red biases show horizontal
      banding, but the blue ones look ok - they do not show chip 2
      noise (T=-3.4 C, like yesterday morning, another low-temp data
      point with no apparent noise).