M83 - The Southern Pinwheel Galaxy in Hydra
M83 - The Southern Pinwheel Galaxy in Hydra
M83 - The Southern Pinwheel Galaxy in Hydra
M83 is a spectacular grand design barred spiral galaxy that is commonly known as the Southern Pinwheel Galaxy. M83 is a starburst galaxy - a galaxy where a great deal of star formation is taking place. As such, the galaxy shows numerous beautiful Ha regions. M83 also has generated 6 observed supernovae in the last century, making it one of the most prolific supernova producers.

In this image, North is up, This image is cropped to 48% of the original full frame.

Exposure Details
Lens Celestron C-8 SCT with Celestron focal reducer
Focal Length 1160mm (measured from the image)
Focal Ratio f/5.8
Mount Schaefer GEM - 7 1/2 Byers gear
Guiding ONAG On-Axis Guider, Lodestar autoguider, PHD Guiding
Camera Canon 450D - Gary Honis modified
Exposure 173 subexposures of 180 seconds each at ISO 1600 - over 8 1/2 hours total
Calibration 30 darks, 30 flats, 30 bias
Date May 16, 19, and 21, 2012
Temperature 58F on 5/16, 56F on 5/19, 59F on 5/21
SQM Reading 21.1 (Bortle 4) on 5/16 and 5/19, 21.0 (Bortle 4) on 5/21
Seeing 4/5 on 5/16, 5/5 on 5/19, 3/5 on 5/21
Location Pine Mountain Club, California
Software Used Images Plus 4.5 for camera control, calibration, stacking, digital development, multiresolution sharpening, smoothing and noise reduction, and realignment of color channels. Photoshop CS5 used for levels and curves, color correction, selective color, high pass filter, star shrinking, lab color, saturation adjustments, screen mask invert, lens correction, and smart sharpen. Gradient Xterminator for gradient removal. Carboni Tools for additional saturation adjustments, noise reduction, and smoothing. HLVG for additional color correction.
Notes M83 is located well into the Southern Hemisphere at a declination of -30 degrees. As such, it is very low in the my sky. While photographing this object, M83 was always between 20 and 25 degrees high. This makes imaging very difficult, as the thick atmosphere causes seeing effects that tend to wash out the fine details. I'm extremely happy with the sharpness of this image, as I had expected a much blurrier image from an object so low in the sky.

This image was published by Astronomy Magazine as its Picture of the Day for July 5, 2012. Its my second Astronomy Magazine Picture of the Day!

This image also earned 1st place in Astrophotogallery.org's June 2012 "Hard-Galaxy" category.

This image also won 1st place in the DSLR category of Cloudy Night's June 2012 Image and Sketching contest.

This image was published in the Fall 2014 issue of Amateur Astronomy Magazine in my article entitled "Processing Wide Field Images: The Taming of the Stars".

This image was also published in the May 2017 edition of Nature Friend Magazine".

And, this image was chosen again by Astronomy Magazine as its Picture of the Day for June 6, 2018!