• Sh 2-188 in Cassiopeia, the Shrimp Nebula
    • Sh 2-188 in Cassiopeia
    Annotated image
  • Sharpless 2-188, the Shrimp Nebula, is a crescent shaped
  • planetary nebula in Cassiopeia.  Its shape is a result of
  • the motion of the central star as it travels through
  • space.  Sh 2-188 is 13 ly across and 850 ly from us.
  • Hover over the image for an annotated view.
  • Date:  26 and 30 September 2025
  • FOV:  cropped to 27' × 18;  Sh 2-188 is about 10' across
  • Telescope:  Celestron C14 SCT (3910mm, f/11)
  • Starizona SCT Coma Corrector/Reducer (2668.5mm, f/7.5)
  • Guiding:  ZWO183 MM
  • 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:  0.292 arcsec/pixel
  • Filter:  Optolong UV/IR and Optolong L-Ultimate
  • Frames:  eighteen 300 second subs Optolong UV/IR  26 Sept
  • forty-nine 300 second subs Optolong LUltimate  26 and 30 Sept
  • Stacking:  sixty-eight 300 second frames using PixInsight
  • Calibration frames: 20 dark, 20 flat, 20 dark flat per session
  • Total Time:  5 hours 35 minutes
  • Processing:  Pixinsight
  • Optolong UVIR data:
  • SPCC, DBE, SPCC, BlurXT, NoiseXT → Linear
  • HTS, GHS, MStr, PixelMath MStr + GHS + HST → Stars,
  • Linear, StarXT, HTS, GHS, MStr,
  • PixelMath MStr + GHS + HST → Starless
  • Optolong L-Ultimate data:
  • SPCC, DBE, SPCC, BlurXT, NoiseXT → Linear
  • HTS, GHS, MStr, PixelMath MStr + GHS + HST → Starless
  • PixelMath ~(~Starless_UVIR*~Starless_L-Ult) → Starless_Blend,
  • HDRMST6PhLm, CurvesTransform
  • PixelMath ~(~Starless_Blend*~Stars) → Final Image
  • Location:  Darling Hill Observatory in Vesper, NY