12P/Pons Brooks 2023-Nov-03 Dan Bartlett

-Two Night "Merger" of Comet 12P/ Pons-Brooks from November 3/4 2023 -
Stacked 24 x180 second exposures of the comet on November 2 (local) and 30 x 180 second exposures on November 3rd. Parallel processing of both nights, standardizing these processes as close as possible, proving ineffective in producing images of equal quality. I suspect the additional 18 minutes of stacking time on the second night as well as varying seeing conditions posed the biggest issue in cometary differences over the two sequential nights. Very "devilish" indeed. However, from the recent outburst last month, the central region is noticeably larger on the second night than the first. This was a surprise to me (See full scale cropped versions) and I don't believe this can be explained via environmental differences alone.

FullResolution: https://astrob.in/3q3azq/D/

I've merged both comet images using the PixelMath "max" function since the overlay would cancel out one or the other cometary features with such a close mosaic pair (large overlap). The comet has moved almost exactly 24 hours from upper right to lower left.

Observational details:
Backyard setup
scope: C14 D = 356mm; fl =729mm; F# 2
camera: asi 2600mcP
exposure: 24 x180 sec (11-02) & 30 x 180sec (11-03)
Seeing: 4/5 both
Transparency: 9/10 both
Observer: DEBartlett


Cropped image details from 2023-11-02:
Projection ............... Gnomonic
Projection origin ........ [1232.384861 1249.790118] px -> [RA: 17 44 41.983 Dec: +41 34 18.43]
Resolution ............... 1.064 arcsec/px
Rotation ................. -0.552 deg
Reference system ......... ICRS
Observation start time ... 2023-11-03 03:56:21 UTC
Observation end time ..... 2023-11-03 03:59:21 UTC
Geodetic coordinates ..... 119 04 46 W 37 46 30 N 2357 m
Focal distance ........... 728.64 mm
Pixel size ............... 3.76 um
Field of view ............ 43' 42.7" x 44' 21.0"
Image center ............. RA: 17 44 41.999 Dec: +41 34 18.33 ex: -0.015172 px ey: +0.125856 px
Image bounds:
top-left .............. RA: 17 46 38.255 Dec: +41 56 35.87 ex: -1.331889 px ey: -1.470600 px
top-right ............. RA: 17 42 43.443 Dec: +41 56 09.10 ex: +2.486236 px ey: -1.827493 px
bottom-left ........... RA: 17 46 39.182 Dec: +41 12 16.81 ex: -1.311451 px ey: -0.085799 px
bottom-right .......... RA: 17 42 47.062 Dec: +41 11 51.27 ex: +1.364838 px ey: +0.389002 px

Cropped image details from 2023-11-03:
Projection ............... Gnomonic
Projection origin ........ [1249.604244 1250.631535] px -> [RA: 17 45 53.559 Dec: +41 25 53.78]
Resolution ............... 1.065 arcsec/px
Rotation ................. -0.559 deg
Reference system ......... ICRS
Observation start time ... 2023-11-04 03:34:10 UTC
Observation end time ..... 2023-11-04 03:37:10 UTC
Geodetic coordinates ..... 119 04 46 W 37 46 30 N 2357 m
Focal distance ........... 728.46 mm
Pixel size ............... 3.76 um
Field of view ............ 44' 21.6" x 44' 21.6"
Image center ............. RA: 17 45 53.504 Dec: +41 25 54.15 ex: -0.083039 px ey: -0.173524 px
Image bounds:
top-left .............. RA: 17 47 51.215 Dec: +41 48 13.17 ex: -1.268442 px ey: -1.513908 px
top-right ............. RA: 17 43 53.369 Dec: +41 47 45.66 ex: +0.121183 px ey: -1.362983 px
bottom-left ........... RA: 17 47 52.101 Dec: +41 03 53.86 ex: -1.975744 px ey: +0.245197 px
bottom-right .......... RA: 17 43 57.025 Dec: +41 03 27.58 ex: +0.336369 px ey: +0.438243 px

Mosaic Image details:
Projection ............... Gnomonic
Projection origin ........ [1192.989714 1610.872895] px -> [RA: 17 45 09.238 Dec: +41 28 07.05]
Resolution ............... 2.128 arcsec/px
Rotation ................. 0.579 deg
Focal distance ........... 1435.14 mm
Pixel size ............... 14.80 um
Field of view ............ 1d 24' 36.3" x 1d 54' 15.0"
Image center ............. RA: 17 45 09.234 Dec: +41 28 06.95 ex: +0.009867 px ey: +0.036294 px
Image bounds:
top-left .............. RA: 17 49 01.166 Dec: +42 24 30.55 ex: -1.644316 px ey: -1.288091 px
top-right ............. RA: 17 41 23.114 Dec: +42 25 23.69 ex: -0.173807 px ey: -1.461401 px
bottom-left ........... RA: 17 48 48.465 Dec: +40 30 22.90 ex: -1.336218 px ey: +0.657033 px
bottom-right .......... RA: 17 41 23.239 Dec: +40 31 15.72 ex: -1.681451 px ey: +1.636192 px