M81 and M82 - Bode's Galaxy and the Cigar Galaxy

M81 and M82 are two prominent members (center) of a larger "M81 Group" of galaxies that are galactic neighbors to our own Local Group galaxies - both groups being part of the greater Virgo Supercluster.  M81, or Bode's Galaxy, was discovered by Johann Elert Bode in 1774 and is the largest member of the group.  At 12 million light years distant it has an apparent magnitude of 6.94 owing to a bright active galactic nucleus, home to a 70 million solar mass supermassive black hole.  A relatively recent tidal encounter with M82 (estimated at 200-600 million years ago) resulted in significant contraction of the spiral arms of M81 and a burst of new star formation.  This is evident in the image by the dominance of blue light in the spiral arms and knots of red Hα emission.  The red Hα emission emanating from the core of M82 is also a result of the encounter, and is the result of a massive amount of gas contraction and star formation leading to a "starburst" galaxy, the archetypal and closest example of this occurrence  Many other galaxies are visible in this wide-field image of the region.