POX 186: A Tiny Galaxy is Born
The distorted shape of this tiny object, called POX 186, is evidence that it is a dwarf galaxy in the process of formation. This image, obtained by NASA's Hubble Space Telescope, shows the bluish-white glow of newborn stars at the galaxy's core, and an arch of stars (at right). Both features suggest a recent collision between two smaller clumps of stars that occurred within the past 100 million years. Gravity will eventually pull these stars together into a more symmetrical form. The red objects at the edges of the images are most likely more distant galaxies.
The Hubble images reveal POX 186 to be extremely small by galaxy standards, measuring only about 900 light-years across and containing just 10 million stars. By contrast, the Milky Way galaxy is about 100,000 light-years across and contains over 100 billion stars.
The galaxy is 68 million light-years away in the constellation Virgo. This color image was created from a composite of three pictures obtained by the Wide Field and Planetary Camera 2 in March and June 2000, and approximates what the galaxy would look like to the human eye.