Observing on a cold clear night

Reports for 2019
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Joined: Fri Jun 13, 2003 9:03 pm

Observing on a cold clear night

Unread post by Pete »

Saturday, 7 Dec 2019 - and a wonderful forecast for tonight. Temperature outside the dome starts out at 27°F.

6047 is a dim 19.4 magnitude Apollo. Used 4-minute exposures but there’s nothing in 9 frames. And then cloud shut me down for a bit. But it’s cleared by 18:49 enough to be workable on the next target.

492143 is a 2 km sized Apollo now 0.4 AU distant and 18.3 magnitude. Uncertainty level is 1 and apparent motion is 1.6’/hr. Imaged from 19:08 – 19:25 at 3 minute exposure, 2X2 binning, -15°C cooling, 1 Hz guiding. Frames 1, 3 & 5 show dRA = -0.2’ and dDEC = +0.1’. S/N is 9 on the first 2 frames and only 4.8 on the last frame. And FWHM drops from 4.8 in the first frame to 2.8” in the last.

It’s down to 26°F and after the first 492143 image is collected I duck inside to run the astrometry from the warmth of the house.

23110 is a 10 km sized main belt asteroid in the 492142 FOV. It’s 2.2 AU distant, moving at a glacial 0.6’/hr. Using the 3min, 2X2, -15C, 1Hz frames as they collected on the primary target, frames 1-3, 4-6 & 7-9 show dRA = +0/1’ and dDEC = 0. With stacking, S/N improves to 7/1 and FHWM to 3.5”. (Run from the house)

338347 is a 1.5 km sized Amor now 18.2 mag and 0.5 AU out. Uncertainty level is 1 and motion is 1.8’/hr. Imaged from 19:46 – 19:59 at 3 min, 2X2, -15C, 1 Hz. Frames 1, 2 & 3 show dRA = -0.5’ and dDEC = +0.1’ S/N is 10 and FWHM is 4.

Comet P/Wiseman-Skiff attempted at 20:08 but is wiped out by moon on optics.

88959 is a 2 km sized Apollo now 18.8 mag and 0.7 AU distant. Uncertainty level is 2 and motion is 2.1’/hr. Imaged from 20:19 – 20:46 at 2 ½ min, 2X2, -15C, 2 Hz. Stacking, frames 1-3, 4-5 & 6-8 show dRA = +0.2’ and dDEC = -0.1’ S/N is crappy (over the roof of the warm house). Approximately 6/1. And FWHM gets dicey ranging from 4.0” to a really insufficient 2.0”

IC 342 (aka Caldwell 5) (aka The Hidden Galaxy) is 9.1 magnitude and somewhere between 7 to 11 million LY distant. Imaging initiated at 21:07. Changed to 1X1 full resolution binning. Cooled to -15°C and guided on a 9th magnitude star at an easy 3 Hz. Seeing is really good. Transparency is really good. First 3 frames run with a 5 minute exposure, and since it appeared that longer would work subsequent exposures at 8 minutes.
(Would have liked to have run longer 15 minute exposures at -30°C but didn't have the darks available.)

In at 23:45 hrs. It’s down to 21° now. 12 observations forwarded to the MPC. Most of the second half of the evening was spent working from inside the house. Not yet acclimated to the deep cold of night.

Pete P.
Bruce D
Life Member
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Joined: Sat Jun 14, 2003 6:10 am

Re: Observing on a cold clear night

Unread post by Bruce D »

Nice Pete!
Bruce D
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