• M8, M20, and M21 in Sagittarius
    • M8, M20, and M21
    Annotated image
  • This wide field of view in Sagittarius contains numerous
  • deep sky objects including the Lagoon Nebula (M8),
  • the Trifid Nebula (M20), and open cluster M21.
  • Also shown are nebulae IC 1274, IC 1275, IC 4684, and NGC 6526,
  • open clusters NGC 6530, and NGC 6546,
  • globular clusters NGC 6553 and NGC 6544, and
  • star forming region NGC 6559.
  • Hover over the picture for an annotated version
  • Date:  22 July 2023 and 13 July 2024
  • FOV:  4° 22' × 2° 55'; the angular size of M24 is about 120' × 60'
  • Telescope:  Askar FRA300 pro (300mm f/5 Petzval)
  • Guiding:  ZWO ASI120MM mini mono guide camera,
  • SVBony SV165 Mini 40mm f/4 guide scope
  • Computer:  ASIair pro Raspberry Pi
  • Mount:  ZWO AM5 mount
  • Camera:  ZWO ASI6200MC Pro Cooled (-10°C) Color CMOS
  • Pixel size:  3.76 μm
  • Resolution:  2.596 arcsec/pixel
  • Frames:22 July 2335 × 240 seconds × 100 gain,
  • 13 July 2452 × 240 seconds × 300 gain
  • Filter:  Baader Light Pollution Moonglow filter with IR cut (22 July 2023)
  • Optolong UV-IR Cut filter (13 July 2024)
  • Stacking:  eighty-seven 240 second frames using Pixinsight
  • Calibration frames:  20 dark, 20 flat, 20 dark flats each session
  • Total Time:  5 hours and 48 minutes
  • Processing:  Pixinsight – PMath ScreenBlend ~(~2023*~2024),
  • SPCC, DBE, SPCC, BXT, NXT, HST, GHS, MStr,
  • PMath 5MStr + 3GHS + 2HST → PM,
  • HDR8_9ph, Sat, and Scale
  • Location:  Darling Hill Observatory near Vesper, NY (22 July 2023)
  • Cherry Springs State Park, near Coudersport, PA (13 July 2024)