• Messier 57 in Lyra, the Ring Nebula
    • M57 in Lyra, Ring Nebula
    Annotated image
  • NGC 5720, M57 or the Ring Nebula, is a planetary nebula in Lyra.
  • The spiral galaxy IC 1296 is visible at about 8 o'clock.
  • Hover over the image for an annotated view.
  • Date:  25, 27, 28, and 31 July and 22 August 2025
  • FOV:  cropped to 10' × 6' 40"; M57 is about 1.4'
  • Telescope:  Celestron C14 SCT (3910mm, f/11)
  • Starizona SCT Coma Corrector/Reducer (2668.5mm, f/7.5)
  • Guiding:  ZWO2600 MC Duo internal ASI220MM mini
  • Computer:  ASIair plus 256GB
  • Mount:  iOptron CEM120
  • Camera:  ZWO ASI2600MC Pro Cooled (0°C) Color CMOS with gain 100
  • Pixel size:  3.76 μm
  • Resolution:  0.291 arcsec/pixel
  • Frames:25 July12 × 300 seconds × 100 gain,
  • 27 July29 × 300 seconds × 100 gain,
  • 28 July29 × 300 seconds × 100 gain,
  • 31 July52 × 300 seconds × 100 gain,
  • 22 August 27 × 300 seconds × 300 gain,
  • 27 August 12 × 300 seconds × 300 gain
  • Filter:  Optolong L-eNhance25 July 2025
  • Optolong L-Ultimate 27, 28, 31 July, 22, and 27 August 2025
  • Stacking:  one hundred thirty-three 300 second frames using PixInsight
  • Calibration frames: 20 dark, 20 flat, 20 dark flat for each session
  • Total Time:  13 hours 40 minutes
  • Processing:  Pixinsight – DynAlign LeNh, LUlt_100g, LUlt_300g
  • HDRComposition LUlt_100g + LUlt_300g → HDR_LUlt,
  • SPCC, DBE, SPCC, BlurXT, NoiseXT → Linear
  • for both LeNh and HDR_LUlt,
  • HTS, GHS, MStr, PixelMath MStr + GHS + HST → Stars,
  • Linear, StarXT, HTS, GHS, MStr,
  • PixelMath MStr + GHS + HST → Starless_LeNh
  • Linear, StarXT, HTS, GHS, MStr,
  • PixelMath MStr + GHS + HST → Starless_LUlt
  • PixelMath ~(~Starless_LeNh*~Starless_LUlt) → Starless,
  • HDRMST_3_5_PhLm,
  • PixelMath ~(~Starless*~Stars) → Blend
  • Location:  Darling Hill Observatory in Vesper, NY