SaratogaSkies Jim Solomon's Astropics


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M97 & M108 (Owl Nebula & Galaxy)

Click to see high-res version.

Image Details:

Camera: Canon Digital Rebel (300D)
Mount: Celestron AS-GT
Scope: Celestron C8-N (8" f/5 Newtonian)
Configuration: Prime Focus
Additional Optics: Celestron/Baader Multi Purpose Coma Corrector (MPCC)
Filter: None
Effective Focal Length: 1000mm
Effective Focal Ratio: f/5
Exposure: 34 x 5min @ ISO 800
Total Exposure: 2hrs, 50min
Date: 5/2/2005 9:47:05 PM PDT (start)
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: None
Guiding: GuideDog via Philips ToUcam Pro II (840k) through Orion ST80 w/ Celestron 2x "Kit" Barlow


  • IRIS: Dark subtraction, registration, gradient removal
  • JimP: Flat field, Kappa-Sigma Stacking, White balance, ASINH stretching
  • Photoshop: Levels, cropping, JPG conversion

Image Description:

This is M97, aka, the Owl Nebula (lower right) and M108, an edge-on spiral galaxy (upper left), both in the constellation of Ursa Major. Conditions were pretty good this night but I went to play ice hockey instead of sitting around here dithering between each frame. That lack of dithering resulted in some pattern noise in the background, which further limited the amount of ASINH stretching that could be done. At least we won the hockey game. <grin> This is the full frame, scaled for display on the web. A higher-resolution image is also available. North is left.