M101_April2017_HomCavObservatory by homcavobservatory Via Flickr: M101 is a face-on, grand design spiral galaxy lying approximately 21 million light-years from Earth. Containing the equivilant of 1 trillion solar masses, it spans about 170,000 light-years from edge-to-edge. Fairly large, it appears over 28 arcminutes in diameter in our sky (i.e. approximately the size of the full moon), and can be found in the constellation of Ursa Major. Often referred to as the Pinwheel galaxy, it shares that moniker with the galaxy M33 in Triangulum. The attached image is via our wide-field imaging system and covers over 3 degrees (i.e. 6 full moons) in width, with North at left. Several other smaller and fainter galaxies can found near M101's; to it's lower right is the round galaxy NGC 5474, to it's upper left the edge-on spiral galaxy NGC 5422 and to it's lower left and just discernible in this image are NGC 5473, 5485 & 5486. Taken by Jay Edwards at the HomCav Observatory in Maine, NY while out shooting the most recent comets on the morning of April 19th using an Orion ED80T CF Triplet Apochromatic Refractor connected to a 0.8x Televue field flattener & focal reducer, CamRanger, IPad and Canon 700D DSLR; and guided by an Orion StarShoot autoguider connected to a Celestron 80MM short tube refractor; all riding on an Orion SkyView Pro goto mount guided by PHD, this image is nearly full frame and has been resized down here to HD resolution and the bit depth lowered from 16 to 8 bits per channel to reduce the file size.