103P/Hartley 2023-Aug-15 Dan Bartlett

13th Magnitude Comet 103P/ Hartley Ghosts Mirach and the Ghost of Mirach (NGC 404) 2023-08-15. Tight on the framing since I wanted to make sure that any potential cometary tail would fit in the frame over the 80 minute exposure time. That placed 2nd magnitude Beta Andromedae (Mirach) on the edge of the field for poor framing. To permit an easier view of the elliptical galaxy, NGC404 (Mirach's Ghost), to shine through, Mirach's halo I had to severely limit that halo's brightness. I then cheated by darkening the entire background, eliminating any chance of seeing the typical IFN within the FOV. I'm not fond of the results but will leave it as is since I have more comet images to process.

Comet 103P/ Hartley continues to brighten and close in on both the Earth and sun's perihelion (predicted to be at the comet's brightest) in early October. We'll see...

Observational details:
Backyard setup
scope: C14 D = 356mm; fl =729mm; F# 2
camera: asi 2600mcP
exposure: 80 x60 sec
Seeing: 4/5
Transparency: 9/10
Observer: DEBartlett
Location: June Lake, California, USA

Image Details (all)
WCS transformation ....... Linear
Projection ............... Gnomonic
Projection origin ........ [1030.039173 1519.977604] px -> [RA: 1 06 45.448 Dec: +36 01 31.68]
Resolution ............... 2.127 arcsec/px
Rotation ................. -3.943 deg
Reference system ......... ICRS
Observation start time ... 2023-08-15 10:26:09 UTC
Observation end time ..... 2023-08-15 10:27:09 UTC
Geodetic coordinates ..... 119 04 46 W 37 46 30 N 2357 m
Focal distance ........... 729.30 mm
Pixel size ............... 7.52 um
Field of view ............ 1d 13' 2.5" x 1d 47' 47.3"
Image center ............. RA: 1 06 45.455 Dec: +36 01 31.63
Image bounds:
top-left .............. RA: 1 09 29.241 Dec: +36 57 40.65
top-right ............. RA: 1 03 24.639 Dec: +36 52 34.45
bottom-left ........... RA: 1 10 01.966 Dec: +35 10 08.34
bottom-right .......... RA: 1 04 05.522 Dec: +35 05 09.03

ASTROBIN image link here