New views of an ancient galaxy

A nearby galaxy, that bears the name of the ancient Ethiopian princess Andromedas name, is revealing some of its cosmic secrets thanks to infrared imagery technology aboard NASAs Spitzer Space Telescope, a close cousin to the more famous Hubble Space Telescope. A team of astronomers discovered that the mammoth galaxy glows with the thermonuclear energy of four billion suns. Based on recent measurements, the team estimated that there are one trillion starsgive or take a few thousandin the Andromeda galaxy. Our own Milky Way galaxy is smaller in comparisonwith a mere 100 billion stars. "What's really interesting about this new view of andromeda is the contrast between the galaxy's smooth, flat disk of old stars and its bumpy waves of dust heated by young stars," said Dr. Pauline Barmby of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. Barmby and company used the infrared Spitzer Space Telescope to study the awesome galaxy. What they observed was something most astronomers never anticipated. NASAs 2005 false-colored portrait of Andromeda shows vast lanes of cosmic dust swirling in the galaxys spiral arms. It is in the spiral arms of galaxies where new stars and planets most likely form. The Andromeda galaxy (aka Messier 31) is approximately 2.5 million light-years away in the constellation Andromeda; the sunlight we see from this galaxy left it 2.5 million years ago . The fuzzy cloud of Andromeda can be seen with the naked eye on a clear night. Andromeda is 260,000 light-years in diameter. Our Milky Way is about 100,000 light-years across making Andromeda a far larger galaxy. Whats in the Sky: The constellation Orion, the hunter, is returning in the night sky for winter. See if you can identify his belt of three stars rising from the south-southeastern horizon this weekend.

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