• NGC 6405, M6, the Butterfly Cluster
    • M6, the Butterfly Cluster
    Annotated image
  • NGC 6405, M6 the Butterfly Cluster, is
  • an open cluster of stars in Scorpius
  • containing about 120 stars
  • located 1.59 kly from us.
  • Hover over the picture for an annotated view.
  • Date:  29 June 2025
  • FOV:  approximately 45' × 30'
  • the angular size of M6 is about 25'
  • Rotation:  −0.004°
  • Telescope:  Stellarvue SVX102T + SFFX-1 (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 ASI6200MC Pro Cooled (-10°C), APS/c mode, gain 100
  • Filter:  Optolong UV/IR cut
  • Stacking:  Twenty-one 240 second frames using PixInsight
  • Calibration:  20 darks, 20 flaats, 20 dark flats
  • Total Time:  1 hour 24 minutes
  • Processing:  Pixinsight
  • SPCC, DBE, SPCC, BlurXT, NoiseXT → Linear
  • HTS, GHS, MStr, PixelMath MStr + GHS + HST → Stars,
  • Linear, StarXT, HTS, GHS, MStr,
  • PixelMath MStr + GHS + HST → Starless
  • PixelMath ~(~Starless_Blend*~Stars) → Final Image
  • Location:  Darling Hill Observatory in Vesper, NY