2023a3 20241025 dbartlett

C2023A3_Tsuchinshan_ATLAS_RASA11_asi6200mcP_4xPanel_Mosaic_35x30sec_30x30sec_30x30sec_19x30sec_2024_10_24_192929local_JuneLake_California_USA_DEBartlett
 
 
 
Another 4x Panel Mosaic.  Over the course of only two equally stable and transparent nights, Comet C/2023 A3 Tsuchinshan-ATLAS has had its tail length reduced nearly two degrees (see https://astrob.in/iqt9w1/B/ ) and visually has dimmed in naked eye visibility to averted vision only.  At least that's my impression following this comet regularly since October 12th.
 
 
 
Notes:
1.  Details in the tail and coma appear to be sharpening as the dusty comet's orientation to us improves.
2.  Although the coma has a small green envelope, the coloration in the plasma tail (which is plainly seen  as striations) is still shrouded by dust.  Perhaps more time on target will bring out  this coloration.  Time will indicate.  My Bortle 1 skies as of late, and 2357m with nearly ideal conditions has not produced.
3.  Once again, SpectrophotometricColorCalibration process was used to calibrate the comet/star color.
4.  ASTROBIN doesn't allow the complete 157MB 4x Panel Mosaic at full resolution.
5.  Still worth a closer look.
???????Dan
 
 
 
Full resolution link:
https://astrob.in/vsuz8j/0/
 
 
 
Observational Notes:
scope: RASA11  fl620mm F/2
Seeing: 4/5
Transparency: 9.5/10
Observer: DEBartlett
Place: JuneLake California USA (Altitude +2357m)
 
Image Info (all ):
Down sampled 2x2 (CMOS = BIN 2x2); 4x4 for FaceBook and the rest.
(All images processed solely using PixInsight)
 
 
 
Panel1:
Projection ............... Gnomonic
Projection origin ........ [4632.011004 3033.868739] px -> [RA: 17 20 25.438  Dec:  +3 31 09.42]
Resolution ............... 2.506arcsec/px
Rotation ................. 1.607 deg
Reference system ......... ICRS
Observation start time ... 2024-10-25 02:10:26 UTC
Observation end time ..... 2024-10-25 02:48:03 UTC
Geodetic coordinates ..... 119 04 46 W  37 46 30 N  2357 m
Focal distance ........... 619.05 mm
Pixel size ............... 3.76 um
Field of view ............ 3d 13' 26.0" x 2d 6' 42.0"
Image center ............. RA: 17 20 25.438  Dec:  +3 31 09.42  ex: +0.003164 px  ey: +0.011006 px
Image bounds:
   top-left .............. RA: 17 27 00.566  Dec:  +4 31 41.99  ex: -1.130733 px  ey: -0.968485 px
   top-right ............. RA: 17 14 04.501  Dec:  +4 37 04.22  ex: +1.103851 px  ey: -1.423818 px
   bottom-left ........... RA: 17 26 45.351  Dec:  +2 25 04.23  ex: -1.095926 px  ey: +0.066849 px
   bottom-right .......... RA: 17 13 51.021  Dec:  +2 30 22.47  ex: +2.196148 px  ey: +0.131208 px
 
Panel2:
Projection ............... Gnomonic
Projection origin ........ [4632.029228 3033.895328] px -> [RA: 17 30 44.546  Dec:  +4 02 43.73]
Resolution ............... 2.506 arcsec/px
Rotation ................. 1.612 deg
Reference system ......... ICRS
Observation start time ... 2024-10-25 02:49:58 UTC
Observation end time ..... 2024-10-25 03:21:16 UTC
Geodetic coordinates ..... 119 04 46 W  37 46 30 N  2357 m
Focal distance ........... 619.00 mm
Pixel size ............... 3.76 um
Field of view ............ 3d 13' 27.0" x 2d 6' 42.7"
Image center ............. RA: 17 30 44.546  Dec:  +4 02 43.73  ex: +0.001790 px  ey: -0.007666 px
Image bounds:
   top-left .............. RA: 17 37 20.050  Dec:  +5 03 15.94  ex: -1.147344 px  ey: -1.043451 px
   top-right ............. RA: 17 24 23.365  Dec:  +5 08 38.35  ex: +1.196006 px  ey: -1.094685 px
   bottom-left ........... RA: 17 37 04.613  Dec:  +2 56 36.38  ex: -1.097285 px  ey: -0.014923 px
   bottom-right .......... RA: 17 24 09.915  Dec:  +3 01 56.38  ex: +2.174706 px  ey: +0.098033 px
 
Panel3:
Projection ............... Gnomonic
Projection origin ........ [4632.018414 3033.795488] px -> [RA: 17 41 22.114  Dec:  +4 42 03.49]
Resolution ............... 2.506 arcsec/px
Rotation ................. 1.631 deg
Reference system ......... ICRS
Observation start time ... 2024-10-25 03:22:52 UTC
Observation end time ..... 2024-10-25 03:54:18 UTC
Geodetic coordinates ..... 119 04 46 W  37 46 30 N  2357 m
Focal distance ........... 618.90 mm
Pixel size ............... 3.76 um
Field of view ............ 3d 13' 28.9" x 2d 6' 43.9"
Image center ............. RA: 17 41 22.114  Dec:  +4 42 03.48  ex: -0.003467 px  ey: -0.040734 px
Image bounds:
   top-left .............. RA: 17 47 58.258  Dec:  +5 42 34.40  ex: -1.474960 px  ey: -0.941112 px
   top-right ............. RA: 17 35 00.492  Dec:  +5 47 57.89  ex: +1.238162 px  ey: -1.603701 px
   bottom-left ........... RA: 17 47 42.436  Dec:  +3 35 55.04  ex: -1.091186 px  ey: +0.079600 px
   bottom-right .......... RA: 17 34 46.923  Dec:  +3 41 14.05  ex: +1.959300 px  ey: +0.192295 px
 
Panel4:
Projection ............... Gnomonic
Projection origin ........ [4632.064500 3033.987853] px -> [RA: 17 50 42.444  Dec:  +5 41 03.88]
Resolution ............... 2.506 arcsec/px
Rotation ................. 1.638 deg
Reference system ......... ICRS
Observation start time ... 2024-10-25 03:55:55 UTC
Observation end time ..... 2024-10-25 04:14:22 UTC
Geodetic coordinates ..... 119 04 46 W  37 46 30 N  2357 m
Focal distance ........... 618.73 mm
Pixel size ............... 3.76 um
Field of view ............ 3d 13' 32.1" x 2d 6' 46.0"
Image center ............. RA: 17 50 42.444  Dec:  +5 41 03.88  ex: +0.010795 px  ey: +0.005799 px
Image bounds:
   top-left .............. RA: 17 57 19.469  Dec:  +6 41 34.47  ex: -1.680819 px  ey: -1.072081 px
   top-right ............. RA: 17 44 20.117  Dec:  +6 46 57.75  ex: +1.155531 px  ey: -1.199255 px
   bottom-left ........... RA: 17 57 03.204  Dec:  +4 34 53.46  ex: -1.105040 px  ey: +0.075855 px
   bottom-right .......... RA: 17 44 06.664  Dec:  +4 40 13.38  ex: +2.197017 px  ey: -0.047068 px