Observers: Jason Harris, Paul Martini, Jose Prieto TO: David Gonzalez Instrument Support: John Hill

Almanac:
Sunset ( 3000 m horizon): 18 55 MST; Sunrise: 5 45 MST
Evening twilight: 20:12 MST; LMST at evening twilight: 09:12
Morning twilight: 04:29 MST; LMST at morning twilight: 17:30
12-degr twilight: 19:41 MST -> 4 59 MST; night center: 00:20

MST Moonrise: 02:47 MST
Moon illuminated fraction: 0.333

$ 00:07: Partly cloudy, wind gusting to 45 mph. Took 25 Bias frames. John is working on collimating the red channel side of the telescope while we wait for sunset.

$ 02:00: Clouds are clearing, but not gone. Telescope SX mirror ventilation system wasn't running, but John fixed it by cycling the breaker. Start Sky flats.

$ 02:10: Test U had 10,000 counts, so using scaling = 5.0
U flat levels: 30000, ..., 18000, 14000, 11000

$ 02:20: Using scaling=7 for B
B flat levels: 28000, 22000, 17000, 16000, 12000

$ 02:25: Using scaling=40 for R
R flat levels: 18000, 11000, 8500, 7500

$ 02:34: Focus at position of mpobj3

$ 02:58: Started mpobj3_1_g. Seeing is 1.0 arcsec. We had guessed it would be 1.5, and went to mpobj3 based on the scheduler's priority for 1.5. Also observed mpobj3_1_r

$ 03:50: Started GRB070412.
Created OB manually from a pre-existing GRB OB. This GRB was discovered 2 hours ago!

Seeing is about 1 arcsec. Clouds moving in fast, so we did not run a focus sequence first. Completed OB...clouds haven't moved in yet. Trying a focus run to see if seeing is much better after refocusing. Also, since seeing is not so good, Peter asked for a second OB, so we're doing that.

$ 04:15: Started second OB for GRB070412.
seeing now about 1.4 despite the refocusing, so conditions have worsened...

$ 04:40: back to mpobj3; the clouds are miraculously holding off. Focus run first, made minor adjustments

$ 04:47: Started mpobj3_2_g. First exposure has horizontal artifacts by the bright stars, due to wind gusts interrupting the guiding...probably still usable Second exposure: the wind gusts obliterated guiding here, this image is not usable.

$ 05:10: We are moving to a new target in the East, in order to point away from the wind. Selecting mpobj4 from the list (KB04 was a possibility, but we aren't confident of a 4-hour block of time under these conditions). mpobj04 has HA=-02:20 Focus run first...Aborted.

$ 05:18: closing due to clouds

$ 07:35: The satellite images show clouds all around, but there are stars above, so we'll give it a shot. We want to finish mpobj3, but we're concerned that the wind will continue to give us problems with the guiding. Instead, we will try mpobj4, which is transiting soon, north of zenith. (Again, I assumed poor seeing here in the scheduler)

$ 07:47: Focus -- It's too cloudy to focus...it was worth a try!

$ 11:20: We've been trying every so often to see if the clouds clear up. So far, it's not good.

$ 11:48: The clouds finally broke, but now the wind is too strong.

(this was written by Jason Harris, using John Hill's wiki account) -- JohnHill - 12 Apr 2007
Topic revision: r3 - 16 Apr 2007, JohnHill
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