Andromeda gets bigger.Visible even to the naked eye, the starlit, spiral disk of the Andromeda galaxy stretches across a patch of sky as wide as the full moon. A new investigation of Earth's next-door-neighbor galaxy reveals that it looms even larger. Using a spectrograph on the Keck II Telescope atop Hawaii's Mauna Kea, astronomers have found that the diameter of Andromeda's disk spans about 220,000 light-years. That's three times the size of previous estimates. A team led by Scott Chapman of the California Institute of Technology California Institute of Technology, at Pasadena, Calif.; originally for men, became coeducational in 1970; founded 1891 as Throop Polytechnic Institute; called Throop College of Technology, 1913–20. in Pasadena and Rodrigo Ibata of the Strasbourg Observatory in France measured the motion toward or away from Earth of some 3,000 relatively old, outlier outlier /out·li·er/ (out´li-er) an observation so distant from the central mass of the data that it noticeably influences results. outlier an extremely high or low value lying beyond the range of the bulk of the data. stars in Andromeda This is the list of notable stars in the constellation Andromeda, sorted by decreasing brightness. Name Designation Location Magnitude Dist. (ly) Sp. class Notes B F HD HIP RA Dec vis. abs. . These outliers were once thought to lie in Andromeda's halo, a spherical distribution of the galaxy's stars that loops around the disk. The analysis shows that the Andromeda outliers are instead fringe residents of the disk and therefore expand the boundary of Andromeda's disk, says Chapman. "Finding [such outliers] over the whole of Andromeda establishes the suspicion that the disk is extended," comments R. Michael Rich of the University of California, Los Angeles UCLA comprises the College of Letters and Science (the primary undergraduate college), seven professional schools, and five professional Health Science schools. Since 2001, UCLA has enrolled over 33,000 total students, and that number is steadily rising. . He and his colleagues had previously found hints of an extended Andromeda disk using the Keck II Telescope and a smaller telescope at the Kitt Peak National Observatory Kitt Peak National Observatory, astronomical observatory located southwest of Tucson, Ariz.; it was founded in 1958 under contract with the National Science Foundation and is administered by the Association of Universities for Research in Astronomy. in Tucson.--R.C. |
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