Andromeda Galaxy Triples In Size
Astronomers find the nearest large-galaxy neighbor to the Milky Way occupies more of the universe than previously thought.
Only a mere 2 million or so light years away, the Andromeda galaxy was at one time thought to be part of the Milky Way. Astronomer Edwin Hubble, whose name graces the Space Telescope, proved in 1923 that Andromeda was a separate spiral galaxy.
Now, astronomers measuring stellar motion in Andromeda have found evidence that the galaxy has a greater reach, according to a Space.com report. A team of astronomers studying 5,000 stars in Andromeda found their motion more orderly than what they expected.
That orderly motion, a rotation around the galaxy’s core, proved a surprising discovery, according to scientists sharing the research information at the 206th meeting of the American Astronomical Society.
A research project to measure the speeds of stars in the farthest outskirts of Andromeda found they were acting as part of the galaxy’s rotating disk, and not moving along random paths. Further, the outer rotating stars seem to occupy about 20 clumps, an organization not considered to be part of the main galaxy.
To have these clumps present, scientists theorize that Andromeda may have collided with other galaxies, which then merged with Andromeda. If this theory proves correct, the event would have happened around 200 million years in the past.
David Utter is a staff writer for WebProNews covering technology and business. Email him here.