Pinwheel Spiral Galaxy in Ursa Major
July 04, 2013
Photographer: John Chumack
Summary Author: John Chumack
Shown above is the Pinwheel Spiral Galaxy (M101) in Ursa Major, the closest face-on Sc class spiral galaxy to us -- about 21 million lights years away. M101 was the first galaxy ever seen as a spiral. In 1851, a Irish amateur astronomer, Lord Rosse, drew M101 after viewing it through a giant telescope he had designed and built himself. In his time, many astronomers thought this feature was a spiral nebula within our Milky Way galaxy. The Pinwheel Galaxy is visible with binoculars, from dark locations, just north of the end star (Alkaid) in the handle of the Big Dipper (Ursa Major).
The Pinwheel Galaxy is approximately seventy percent larger than the Milky Way. The tiny, bright blue dots in the spiral arms are young, hot, blue star clusters. Little pink spots are star formation regions (H II) -- massive stellar nurseries. It’s estimated that over 3,000 of these H II regions are scattered throughout the Pinwheel’s spiral arms. Note that several background galaxies can be seen in and around the spiral arms. Click on photo to see black and white negative image.
I’ve been imaging the night sky for more than 25 years, using mostly my homemade telescopes and low cost camera equipment. Capturing images like this makes all the time and effort I put in worthwhile! Photo taken at John Bryan State Park Observatory in Yellow Springs, Ohio on June 3, 2013. For image details click here.