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

Processing:

  • 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.

 
M109 (Barred Spiral Galaxy)
SaratogaSkies Jim Solomon's Astropics

Search

Latest news

December: Test shots with new scopes/mounts

Dec 21: TMB 80/480 Arrives!

Dec 3: AP1200 Arrives!

Nov 30: TMB 152/1200 Arrives!

Links:

M109 (Barred Spiral Galaxy)

[Hα+R G B]

Mouse-over to see annotations. (Requires Javascript) Click to see high-res version.

Image Details:

Camera: Mofidied Canon Rebel XT (350D): Hutech Type I Filter Replacement
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: Hutech Hα Front Filter (HA-FF)
Effective Focal Length: 1000mm
Effective Focal Ratio: f/5
Exposure: 42 x 4min @ ISO 400 (RGB), 24 x 16min @ ISO 1600 (Hα)
Total Exposure: 9hrs, 12min
Date: 5/16/2006 and 5/17/2006
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: GADFly 1.0.5
Guiding: GuideDog via Philips ToUcam Pro II (840k) through Orion ST80 w/ Celestron 2x "Kit" Barlow

Processing:

  • IRIS: Dark subtraction, registration, gradient removal
  • JimP: Flat field, Kappa-Sigma Stacking, Hα Combination, White balance, ASINH stretching
  • Photoshop: Sharpening, Levels, cropping, JPG conversion
  • Neat Image: Noise reduction

Image Description:

This is M109, a Barred Spiral Galaxy in the constellation of Ursa Major. This is also First Light for my new Hutech Hα Front Filter (HA-FF). For this image, I captured 6.4 hours of Hα over two nights, and 2.8 hours of RGB data on a third night. Not sure it was worth it. .

The Hα regions, such that they are, appear as the small, cherry-red regions in the spiral arms of the galaxy (see the full-resolution image). M109 turned out to be a poor choice of target for testing the Hα filter. This is because the Hα regions in M109 are very small; i.e., not easily resolved, even at the reasonably long focal length of my Newtonian (1000mm). Of course, using a DSLR doesn't help, since the Bayer matrix permits only one in every four sensor locations to record the Hα wavelength. M101 and M51 are in my cross-hairs while I wait for the summer Milky Way objects to be well placed at my site (namely, West of the Meridian early at night).

The image above is a slight crop of the full field. A full-resolution image is also available. North is up.