Discover the cosmos! Each day a different image or photograph of
our fascinating universe is featured, along with a brief
explanation written by a professional astronomer. 2003 April 17
Explanation: Close to the Great Bear (Ursa Major) and surrounded
by the stars of the Hunting Dogs (Canes Venatici), this
celestial nebula was discovered in 1781 by the metric French
astronomer Pierre Mechain and later added to the catalog of his
friend and colleague Charles Messier as M106. Modern deep
telescopic views reveal it to be an island universe -- a spiral
galaxy around 30 thousand light-years across located only about
21 million light-years beyond the stars of the Milky Way.
Youthful blue star clusters and reddish stellar nurseries trace
the striking spiral arms of M106. Seen so clearly in this
beautiful image, the galaxy's bright core is also visible across
the spectrum from radio to x-rays, making M106 a nearby example
of the Seyfert class of active galaxies. The bright core of a
Seyfert galaxy is believed to be po