Galactic cannibalism.The Milky Way Milky Way, the galaxy of which the sun and solar system are a part, seen as a broad band of light arching across the night sky from horizon to horizon; if not blocked by the horizon, it would be seen as a circle around the entire sky. has been at it again. Astronomers have found evidence that our home galaxy is tearing apart and swallowing a nearby collection of stars--most likely the remains of a dwarf galaxy dwarf galaxy A small, dim galaxy, intermediate in size between a regular galaxy and a globular cluster. Like larger galaxies, dwarf galaxies are classified as elliptical, spiral, or irregular based on their shape. . The galactic violence would be the latest confirmed act of cannibalism cannibalism (kăn`ĭbəlĭzəm) [Span. caníbal, referring to the Carib], eating of human flesh by other humans. by the Milky Way (SN: 4/22/00, p. 261). Galaxies commonly grow by eating each other. Some 30,000 light-years from Earth, the collection of stars lies within the Milky Way but differs in velocity and shape from that of other known galaxy components. Containing several hundred thousand stars, the group spans a swath of sky larger than any galaxy beyond the Milky Way. Astronomers found the group by combing through distance measurements of 48 million stars recorded by the Sloan Digital Sky Survey The Sloan Digital Sky Survey or SDSS is a major multi-filter imaging and spectroscopic redshift survey using a dedicated 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico. The project was named after the Alfred P. . The data enabled the team to build a three-dimensional map of the Milky Way in which faint star groupings "snapped into view," says Robert Lupton of Princeton University Princeton University, at Princeton, N.J.; coeducational; chartered 1746, opened 1747, rechartered 1748, called the College of New Jersey until 1896. Schools and Research Facilities . He reported the findings in January at a meeting of the American Astronomical Society The American Astronomical Society (AAS, sometimes pronounced "double-A-S") is a US society of professional astronomers and other interested individuals, headquartered in Washington, DC. in Washington, D.C. Another team, reporting in the Jan. 10 Astrophysical Journal Letters, already had evidence that a subset of stars in the same region moves in concert and is probably the remains of a dwarf galaxy. But the Sloan study revealed the breadth of the newfound collection of stars. Because the former galaxy lies considerably closer to the center of the Milky Way than do any other known dwarf-galaxy remains, "it 1s likely to have been chewed up more by the interactions with the Milky Way's gravitational field," says Heather Morrison of Case Western Reserve University in Cleveland.--R.C. |
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