Locations of star-forming regions (dots) superposed on an artist's conception of the Milky Way. The locations have been measured by "triangulation" using the NRAO/NSF Very Long Baseline Array of radio telescopes.
Image Courtesy of Mark Reid, Harvard-Smithsonian Center for Astrophysics; Robert Hurt (NASA/IPAC)
New Galactic Distance Measurements Increase Milky Way's Mass and Rotation Speed
News story originally written on January 30, 2009
Astronomers have learned that our galaxy, called the Milky Way, is rotating faster than they used to think. It also has a bigger mass than they used to think. This means the Milky Way might run into the Andromeda galaxy in about 5 billion years, which is sooner than they used to think.
The Milky Way is a spiral galaxy, with the biggest and youngest stars located in arms that curl around the center. Astronomers think there are probably four spiral arms in the Milky Way galaxy, although it is still possible that the galaxy has only two spiral arms or that there are two bigger arms that contain both old and young stars, along with two smaller arms that have only younger stars.
In order to learn more about this, an astronomer names Mark Reid led a team that made measurements using telescopes in Hawaii, across the United States, and in the U.S. Virgin Islands.
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