This is a LRGB exposure (18:10:10:10 minutes) taken with a STL-1301E CCD camera thru Kopernik's 20-inch telescope. The field of view is about 13x13 arc minutes.
Charles Messier: "Feb. 9th, 1781. Nebula without a star, near the preceding (M81) both appearing in the same field of the telescope. This one is less distinct than the preceding: the light is faint and elongated with a telescopic star in its extremity. (first) Seen by J.E. Bode at Berlin Obs. on Dec. 31st, 1774, and by P. Mechain in August 1779".
Smyth: "Very long, narrow, bright, especially in the northern limb, but paler than M-81".
A companion of M-81. Other members of this group include the peculiar galaxies NGC 3077 & NGC 2976, irregular systems NGC 2366, IC 2574 and Holmberg II, and possibly other fainter galaxies. The large spiral NGC 2403 in Camelopardalis also appears to be a dynamical member of this group. ( We will be providing images, etc of these galaxies soon.) M-82's distance is 8.5 million light years. With a mass of 50 billion solar masses, and a diameter of 16,000 light years, M-82 is a rather small galaxy. It is perhaps only a fifth as large as M-81.
This strange looking object is a source of intense radio waves, and synchrotron radiation. The latter is caused by free electrons spiraling along strong magnetic field lines. Analysis of the light shows material flowing out of the center of the galaxy at 1,000 km/sec. Early theories assumed that M-82 was literally exploding. More recently, some astronomers speculated that the irregular behavior comes from a collision with a dark gas cloud (note the dark perpendicular lanes, obviously in front of the galaxy). However, the current popular theory is that M-82 is a "star burst" galaxy, with intense star formation triggered by tidal forces caused by the nearby and massive M-81. In the nucleus, many massive, young stars have become supernovas. Shockwaves from these explosions are causing the out-flowing material.
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George Normandin, KAS
Revised May 14th, 2005