The Pinwheel Galay, Messier 101, is a face-on spiral galaxy distanced 21 million light-years away in the constellation Ursa Major.
M101 is a large galaxy comparable in size to the Milky Way. With a diameter of 170,000 light-years it is roughly equal the size of the Milky Way. It has a disk mass on the order of 100 billion solar masses, along with a small central bulge of about 3 billion solar masses.
M101 is noted for its high population of H II regions, many of which are very large and bright.
Data captured 5th March, 2016.
21x 4 minute exposures at ISO400.
Orion Europa 200
This image was processed in Pixinsight & Lightroom.