Strange galactic 'dance' a cosmic puzzle    |   Jan. 4, 2013 at
7:46 PM SYDNEY, Jan. 4 (UPI) -- Australian astronomers say
they've been surprised by the discovery of a group of dwarf
galaxies dancing in a ring around the much larger Andromeda
Galaxy.  The observation of small galaxies locked in a strange
dance around a larger one presents a challenge to current
theories of how all galaxies form and evolve, they said.  "When
we looked at the dwarf galaxies surrounding Andromeda, we
expected to find them buzzing around randomly, like angry bees
around a hive," Geraint Lewis from the University of Sydney's
School of Physics said.  "Instead, we've found that half of
Andromeda's satellites are orbiting together in an immense
plane, which is more than a million light-years in diameter but
only 30,000 light years thick," he said in a university release.
"These dwarf galaxies have formed a ring around Andromeda."
These small galaxies, many times fainter than their bright
hosts, were thought to trace a path around th