Spiral galaxy in the constellation Ursa Major.
Messier 81 is a 7.0 mag bright spiral galaxy in the constellation Ursa Major. The apparent area of M81 is only about three percent of the area of the Andromeda Nebula. With 12 million light-years, M81 is a good four times as far away as this galaxy and therefore appears noticeably smaller.
|Date of exposures:||10.04.2016|
|Distance:||12 Mio. Lightyears|
|Exposures:||CLS CCD: 80 x 300", Astrodon RGB E-Series: 143 x 180", Sum: 13,8 hrs.|
|Telescope:||10'', F4 Newton|
|Focal length:||1000 mm|
|Filter:||Astrodon E-Series, Astronomik CCD CLS|
|Camera:||ASI 1600 MMC Pro|
|Guiding:||Off Axis Guider, Lodestar|
With a diameter of 82,000 light years and an estimated 200 billion stars, this galaxy is slightly smaller than the Milky Way. The central black hole has a mass of about 70 million solar masses and is thus about 15 times more massive than the black hole of our galaxy. From Earth, we look obliquely at the galaxy, which has relatively loose spiral arms, but many stars near the center.
My older image from 2016: