The Black Eye
galaxy (or M64 or
was discovered by Edward Pigott in March 1779, and
independently by Johann Elert Bode in April of the same
year, as well as by Charles Messier in 1780. It is a spiral
galaxy in the Coma Berenices constellation and appears
to be a fairly normal spiral galaxy. As in the majority of
galaxies, all of the stars in M64 are orbiting in the same
direction, clockwise as seen in the Hubble image.
However, recent detailed studies have led to the remarkable
discovery that the interstellar gas in the outer regions of
M64 rotates in the opposite
direction from the gas and stars in the inner regions. The
inner region has a radius of only approximately 3,000
light-years, while the outer section extends another 40,000
light-years. This pattern is believed to trigger the
creation of many new stars around the boundary separating
the two regions.
A collision of two galaxies has left a merged star system
with an unusual appearance as well as bizarre internal
motions. Astronomers believe that the oppositely rotating
gas arose when M64 absorbed a satellite galaxy that collided
with it, perhaps more than one billion years ago. Active
formation of new stars is occurring in the shear region
where the oppositely rotating gases collide, are compressed,
Particularly noticeable in the image are hot, blue young
stars that have just formed, along with pink clouds of
glowing hydrogen gas that fluoresce when exposed to
ultraviolet light from newly formed stars. It is
approximately 17 million light years from earth.
The small galaxy that impinged on its neighbour has now been
almost completely destroyed, its stars either merged with
the main galaxy or scattered into space, but signs of the
collision persist in the backward motion of gas at the outer
edge of M64.
This image was chosen
Astroimaging Challenge Yahoo Group
Runner-up May 2009.