M82: Galaxy with a Supergalactic Wind

Explanation: What's lighting up the Cigar Galaxy? M82 , as this irregular galaxy is also known, was stirred up by a recent pass near large spiral galaxy M81 . This doesn't fully explain the source of the red-glowing outwardly expanding gas, however. Recent evidence indicates that this gas is being driven out by the combined emerging particle winds of many stars, together creating a galactic “superwind.” The above photographic mosaic , released yesterday to commemorate the sixteenth anniversary of the Hubble Space Telescope , highlights a specific color of red light strongly emitted by ionized hydrogen gas, showing detailed filaments of this gas. The filaments extend for over 10,000 light year s. The 12-million light-year distant Cigar Galaxy is the brightest galaxy in the sky in infrared light, and can be seen in visible light with a small telescope towards the constellation of Ursa Major .