NGC 7331 and Stephan's Quintet in Pegasus

NGC 7331 is the larger spiral galaxy in the top right.

Stephan's Quintet, in the lower left, is a group of galaxies in

Pegasus that are interacting gravitationally.  The quintet includes

the tight pair NGC 7318a and NGC 7318b.  NGC 7317, NGC 7319,

and NGC 7320c are all gravitationally linked but the blue

galaxy PGC69270 is an optical member of the grouping.

Hover over the picture for an annotated version

Date:  29 September, 18 and 27 October 2022, and 15 September 2023

FOV:  cropped to 74' × 49'; the long axis of Stephan's Quintet is about 5'

Telescope:  Stellarvue SVX102T + SFFX-1 flattener (714mm, f/7)

Guiding:  ZWO ASI120MM mini mono guide camera,

Stellarvue F050G 50mm guide scope

Computer:  ASIair pro Raspberry Pi

Mount:  iOptron CEM40

Camera:  ZWO ASI071MC Pro Cooled (-10°C) Color CMOS with gain 240

Pixel size:  4.78 μm

Resolution:  1.337 arcsec/pixel

Frames:29 Sept 2231 × 240 seconds,

18 Oct 2244 × 240 seconds,

27 Oct 2252 × 240 seconds,

15 Sept 2394 × 240 seconds

Filter:  Baader Light Pollution Moonglow filter with IR cut

Stacking:  Two-hundred-twenty-one 240 second frames using Pixinsight

Calibration frames:  20 dark, 20 flat, 20 dark flat for each session

Total Time:  14 hours 44 minutes

Processing:  Pixinsight – SPCC, DBE, BlurXT, NoiseXT, MStr, GHS, HST,

PMath add Mstr, GHS, HST, HDR4, StarXT,

Bill Blanshan Star Reduction, Sat, Scale

Location:  Darling Hill Observatory near Vesper, NY