The M81 galaxy group is a group of over 40 galaxies located in the constellations Ursa Major and Camelopardalis. The group includes the galaxies Messier 81, Messier 82, and NGC 3077 which are found in this image. The M81 group is one of the closest galaxy groups to the Local Group, which includes the Milky Way, Andromeda, and Triangulum galaxies. The M81 group is about 12 million light-years from Earth.
This image consists of 215 3 minute exposures captured using APT with guiding by PHD2 from the end of January 2024. I imaged this when the moon loomed high in my sky. SkyWatcher Esprit 120ED telescope paired with the ZWO ASI2600MC camera and the Antlia quadband light pollution filter. An annotated version is available on my Astrobin page here.
Bode’s Galaxy, or Messier 81 (M 81), is a spiral galaxy in the constellation Ursa Major. It’s about 11.8 million light-years away from Earth and has an apparent magnitude of 6.94. M81 is one of the brightest galaxies in the night sky and is visible with binoculars or a telescope. Its size and well-defined spiral arms make it an enjoyable sight. M81 is nicknamed “Bode’s Galaxy” after it was discovered by German astronomer Johann Elert Bode in 1774.
Messier 82 (M82) is a spiral galaxy located in the constellation Ursa Major, about 12 million light-years away from Earth. It’s also known as the Cigar Galaxy because it’s undergoing a burst of star formation in its core.
M82 is the second-largest member of the M81 Group, with a mean radius of 18,500 light-years. The galaxy’s center is forming stars 10 times faster than the Milky Way due to gravitational interactions with its neighbor galaxy, M81.
M82’s star formation powers a bipolar superwind that originates near the core of the galaxy. The superwind compresses enough gas to trigger the ignition of millions more stars. The galaxy also expels violent winds that blow gas and dust out of the galaxy. In visible light, the only hint of M82’s star formation is fountains of hot hydrogen gas streaming out of its disk.
NGC 3077 is a small, disrupted elliptical galaxy in the constellation Ursa Major. It is a member of the M81 group of galaxies and is located about 13 million light-years away from Earth. At first glance NGC 3077 looks like a typical, relatively peaceful elliptical galaxy. However, it is actually a hotbed of very energetic star formation and the whole galaxy is laced with dusty tendrils. Despite being similar to an elliptical galaxy in appearance, it is peculiar for two reasons. First, it shows wispy edges and scattered dust clouds that are probably a result of gravitational interaction with its larger neighbors, similar to the galaxy M 82. Second, this galaxy has an active nucleus.
