M81 - Bode's Galaxy in Ursa Major
M81 - Bode's Galaxy in Ursa Major
M81 - Bode's Galaxy in Ursa Major
M81, also known as Bode's Galaxy, is an impressive spiral galaxy in Ursa Major and is the largest galaxy in the M81 group of galaxies. In a telescope, M81 is quite large with an apparent diameter of 27' x 14'. Morever, M81 is only 1/2 degree from its close neighbor, M82. The two galaxies are gravitationally interacting, and the dramatic distortions of M82 are proof positive that M81 is the winner in the collision.

The faint galaxy to the left of M81 is Holmberg IX, a dwarf satellite galaxy of M81.

In this image, North is up. This image is cropped to 64% of the original full frame.

Exposure Details
Lens Celestron C-8 SCT with Celestron focal reducer
Focal Length 1260mm
Focal Ratio f/6.3
Mount Schaefer GEM - 7 1/2
Guiding 80mm f/11 guidescope with PHD Guiding
Camera Canon 450D - Gary Honis modified
Exposure 177 subexposures of 180 seconds at ISO 1600 - just under 9 hours
Calibration 30 darks, 30 flats, 30 bias
Date Feb 16 and 28, 2012 and March 2, 2012
Temperature 34F on 2/16, 30F on 2/28, 43F on 3/2
SQM Reading 21.4 on 2/16, 21.2 on 2/28, 21.3 on 3/2
Seeing 3 of 5 on 2/16 and 2/28, 4 of 5 on 3/2
Location Pine Mountain Club, California
Software Used Images Plus 4.5 for camera control, calibration, stacking, digital development, noise reduction, smoothing, and Lucy-Richardson deconvolution. Photoshop CS5 used for levels and curves, saturation adjustments, star shrinking, noise reduction, high pass filter, and color correction. Carboni Actions for additional saturation adjustments, noise reduction and smoothing. HLVG for addiitonal color correction. Registar for image alignment.
Notes I employed some new processing techniques with image which allowed me to bring out some nice fine details. This image also captured Holmberg IX much better than my previous attempt.

This image won 1st place in Digital Astro's Challenge Photo - Galaxy category for March 2012.

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SUPERCEDED-NEWER VERSION AVAILABLE---M81 - Bode's Galaxy in Ursa Major - May 2011 Version