Atomic Hydrogen in M81
November 4, 2003
The galaxy M81 is a spiral galaxy about 11 million light-years from Earth. It is about 50,000 light-years across. In the optical (not shown), the galaxy is known as a "Grand Design" spiral, for its pair of symmetric, well-defined spiral arms. This image, which only shows the cold atomic hydrogen gas in the galaxy, clearly shows that the gas also follows this grand design pattern. In this pseudocolor image, red indicates higher gas densities and blue weaker emission.
Topics: Technology Internet, Ursa Major constellation, Unbarred spiral galaxies, Spiral galaxies, Grand design spiral galaxy, Messier 82, Messier 81, M81 Group, Messier objects, Galaxy