M101 Pinwheel Galaxy
M101, also known as the Pinwheel Galaxy, is located in the direction of the Ursa Major Constellation at an approximate distance of 25 Million Light-Years. It shows large, colorful and magnificent on an astrophotographic image due to face-on orientation and its very large diameter of around 170,000 light-years, almost twice the size of our own galaxy, the Milky Way. M101 exhibits very large and extremely bright HII regions, producing massive star forming regions of blue stars from the copious amount of available molecular hydrogen and dust. The disrupted left side of the galaxy is thought to have been caused by an encounter with another galaxy in the distant past causing gravitational tidal forces which amplified the density waves in the spiral arms, compressing the gas and dust, and triggering massive star formation. M101's immense gravitational influence seems to be distorting its nearby neighbors.
Object: M101 (Pinwheel Galaxy)
Distance: 25 Million Light-Years
Magnitude: 7.9
Date: June 2009
Place: Fort Davis, TX
Exposure Details: LRGB:550:140:130:150 minutes unbinned
Processing: MaxIm DL, CCDStack, RegiStar, Photoshop CS3
Optics: 12.5" RCOS Truss
Focal Length: 2802mm @ f9
Mount: Paramount ME
Camera: STL6303E
Focuser: RCOS
Guiding: Off-axis with SBIG Guide Camera
Filters: Tru-Balance GenII LRGB 2"