is a face-on spiral galaxy distanced 21 million light-years (six megaparsecs) away from Earth in the constellation Ursa Major. M101 is a large galaxy, with a diameter of 170,000 light-years. By comparison, the Milky Way has a diameter of 100,000 light years. It has around a trillion stars, twice the number in 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.
Source: https://en.wikipedia.org/wiki/Andromeda_Galaxy
A good example showing how a coma mirror can break a nice picture.
- Composition: Astro Pixel Processor,
- Processing: GIMP + plug-ins,
- Lights: 81 x 120[s], ISO 1600,
- Correction frames: Flats, DarkFlats, Darks, Bias
