• Arp 319, Stephan's Quintet, and NGC 7331 in Pegasus
    • NGC 7331 and Stephan's Quintet
    Annotated image
  • Arp 319 is a part of Stephan's Quintet, a group of galaxies in
  • Pegasus that are interacting gravitationally.  Arp 319 is 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.
  • NGC 7331 is the larger spiral galaxy in the top right.
  • 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