A nite for comets

Reports for 2019
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Pete
Astro Day Coordinator
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Joined: Fri Jun 13, 2003 9:03 pm

A nite for comets

Unread post by Pete » Thu Nov 28, 2019 7:48 pm

Tuesday, 26 Nov 2019

Forecast looks good. Out at dusk to run 1X1 flats.

While subsequently creating 1X1 reductions I lost ALL dark and bia frames for everything – a big setback due to clumsy keyboarding and general confusion. As a consequence, ALL of tonight’s observations will be run using CCDSoft’s AUTO DARK feature rather than using full reductions.

It’s a mild evening with initial temperature at 48°F.

Comet C/2018 N2 is moving away but still relatively very bright at 12.9 magnitude. Imaged from 17:31 – 17:44 at 30 seconds exposure, 2X2 binning, -15°C cooling, 2 Hz guiding. Frames 1, 11 & 23 show ∆RA = -0.6’ & ∆Dec = +1.0’ S/N averages 34 and FWHM is consistent at 4.3”.

Image
This is a stack of 22 frames with conventional N up and E left.

3200 Phaethon is a 9 km sized Apollo now 17.6 mag and 1.3 AU from Earth. Observed from 18:14 – 18:33 at 1 ½ min, 2X2, -15C, 2 Hz. Frames 1, 3 & 5 show ∆RA = 0.1’ & ∆Dec = 0. S/N averages 28 and FWHM is consistently good at 3.3”. Photometry is to be reported as 17.1 magnitude.

Comet P/Wiseman-Skiff (114P) is at 14.1 mag and 0.7 AU distant. Imaged from 18:43 – 19:08 at 2 ½ min, 2X2, -15C, 2 Hz. Frames 1, 3 & 5 show ∆RA = +0.8’ & ∆Dec = +0.2’ S/N averages 26 and FWHM is averaging at 4.8”. But seeing’s gone wild.

Image
This is a succession of 9 frames

2019 UO is a recent discovery supposedly 18.8 mag. Searched for it from 19:20 – 19:43. Used 4 minute exposures but still no joy.
88959 is a 2 km sized Apollo now 18.4 mag and 0.6 AU distant. Apparent motion is 3’/hr and uncertainty level is 2. Imaged from 19:51 – 20:05 at 90 sec, 2X2, -15C, 1 Hz. Using track ‘n stack, frames 1-2, 3-4 & 5-6 show ∆RA = +0.3’ & ∆Dec = +0.4’ S/N averages only 6 and FWHM ranges from 4.5 to 5.6”

1620 Geographos is a 6 km sized Apollo now 17.5 mag and 0.9 AU distant. Motion is 1.2’/hr and uncertainty level is 0. Imaged from 20:16 – 20:28 at 2 min, 2X2, -15C, 1 Hz. Frames 1, 2 & 4 show ∆RA = +0.2’ & ∆Dec = 0 S/N ranges wildly from 8.8 to 17.2 while FWHM runs from 3.5” to 4.4”.
36236 is a 4 km sized Apollo now 17.2 mag and 0.8 AU out. Uncertainty level is 2 and motion is 2.5’/hr. Imaged from 20:35 – 20:47 at 2 min, 2X2, -15C, 2 Hz. Frames 1, 2 & 4 show ∆RA = +0.3’ & ∆Dec = -0.2’ S/N averages 44 and FWHM is consistent at 4.5”. Photometry reported to MPC as 17.0 magnitude.

Shut down by cloud. In at 21:00 hrs. Air’s cooled a bit to 42°F. 18 observations forwarded to the MPC.

hgp
Pete P.
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