• Messier 81 and Messier 82 in Ursa Major
    • M81 and M82
    M81 and M82 annotated
  • M81 (NGC 3031), originally Bode's Nebula, was redesignated as
  • Bode's Galaxy after Edwin Hubble classified the great nebula
  • in Andromeda as a galaxy on 5 October, 1923.  M81 lies
  • 11.8 Mly from us, has a diameter of about 90 kly, and
  • appears about 27' on its long axis.  M82 (NGC 3034)
  • is also known as the Cigar Galaxy, a starburst galaxy
  • 12 Mly from us.  It has a diameter of 40.8 kly and an
  • apparent long axis of 11.2'.  PGC28757 is a faint,
  • irregular galaxy visible just below M81.  Also note
  • there is a significant amount of IFN, or integrated
  • flux nebulosity, visible in this picture.
  • Hover over the picture for an annotated version
  • Date:  7 and 11 April 2026
  • FOV:  Cropped to 75' × 50'; M81's long axis is about 27'
  • Rotation:  −90.025°
  • 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:  ZWO AM5N
  • Camera:  ZWO ASI6200MC Pro Cooled (-10°C)
  • Color CMOS set at gain 100 and an APS/c ROI
  • Pixel size:  3.76 μm
  • Resolution:  1.054 arcsec/pixel
  • Filter:  Optolong UV/IR cut
  • Stacking:  one hundred and thirty-four 300 second frames using PixInsight
  • Calibration:  20 Dark, 20 Flat, 20 DarkFlat using PixInsight
  • Total Time:  11 hours 10 minutes
  • Processing:  Pixinsight – DBE, Color Cal with GHS, BlurXT, NoiseXT → Linear
  • MStr, GHS, HST, PMath MStr + GHS + HST → Stars, Sat,
  • StarXT, MStr, GHS, HST, PMath MStr + GHS + HST → Starless,
  • HDRMST86PhLm, Sat, PMath ~(~Stars*~Starless) → Blend, scale
  • Location:  Darling Hill Observatory near Vesper, NY