SaratogaSkies Jim Solomon's Astropics


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M31 (Andromeda Galaxy)   [obsolete]

Image Details:

Camera: Canon Digital Rebel (300D)
Mount: Celestron AS-GT
Scope: Celestron C8-N (8" f/5 Newtonian)
Configuration: Prime Focus
Additional Optics: n/a (Prime)
Filter: None
Effective Focal Length: 1000mm
Effective Focal Ratio: f/5
Exposure: 10 x 5min @ ISO 100
Total Exposure: 0hrs, 50min
Date: 8/16/2004, ~3am PDT
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, flat field, registration, Kappa-Sigma stacking
  • Photoshop: Levels, image size, JPG conversion

Image Description:

This is M31, the Andromeda Galaxy, a "close" neighbor of our own Milky Way. I was still experimenting with autoguiding when I shot this object, so I really didn't capture enough frames to bring out the faint detail in the galaxy's outer arms. It was also in a fairly light-polluted portion of the sky on a night of lousy transparency. Finally, the 1000mm focal length of my 8" Newtonian is too large to fit the entire object in the field of the Digital Rebel's sensor. Sounds like a job for the ST80. Ok, enough whining. The reasonably well-defined fuzzball at the bottom of the image is M32, and the half-a-fuzzball at the top-right is M110, both elliptical galaxies. This is the full frame, scaled for display on the web. North is up.