The Pinwheel Galaxy (also known as Messier 101, M101 or NGC 5457) is a face-on spiral galaxy distanced 21 million light-years (six megaparsecs) away in the constellation Ursa Major, first discovered by Pierre Méchain on March 27, 1781, and communicated to Charles Messier who verified its position for inclusion in the Messier Catalogue as one of its final entries. On August 24, 2011, a Type Ia supernova, SN 2011fe, initially designated PTF 11kly, was discovered in M101. The supernova was visual magnitude17.2 at discovery and reached magnitude 9.9 at its peak. This was the fourth supernova recorded in M101. The first, SN 1909A, was discovered by Max Wolf in January 1909 and reached magnitude 12.1. SN 1951H reached magnitude 17.5 in September 1951 and SN 1970G reached magnitude 11.5 in January 1970.

Imaging telescopes or lenses: Planewave Instruments CDK 12.5″ Corrected Dall-Kirkham Astrograph f/8
Imaging cameras: SBIG STXL 6303
Mounts: Paramount PME
Filters: Astrodon Ha, Astrodon Blue, Astrodon Green, Astrodon Red, Astrodon Luminance
Dates: June 15, 2014, June 18, 2014, July 3, 2014
Frames:
Astrodon Blue: 11×300″ bin 2×2
Astrodon Green: 7×300″ bin 2×2
Astrodon Ha: 5×600″ bin 1×1
Astrodon Luminance: 9×300″ bin 1×1
Astrodon Red: 9×300″ bin 2×2
Integration: 3.8 hours

Author: Giulio Ercolani
AstroPhotography of the day by SPONLI 7 Aug 2014