Messier 101 – The Pinwheel Galaxy in Ursa Major
Messier 101 (NGC 5457), better known as the Pinwheel Galaxy, is a face-on grand-design spiral galaxy in the constellation Ursa Major. It lies at a distance of approximately 21 million light years (≈ 6.4 Mpc) and shines at an apparent magnitude of about 7.9, which puts it within easy reach of a small telescope - provided the sky is dark enough, as its light is spread over an apparent diameter of nearly 29 arc minutes, close to the full Moon's. The galaxy was discovered by Pierre Méchain on 27 March 1781 and reported to Charles Messier, who immediately included it among the very last entries of his famous catalogue (Wikipedia: Pinwheel Galaxy).
The Pinwheel Galaxy M101 (NGC 5457) in Constellation Ursa Major, Telescope Newton f=1000mm f/4, Camera Atik 460Exm with Baader LRGB and Hα filters, Total Exposure Time 22h20min