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alokmohan
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Astronomers have identified 20 new stellar systems in our local solar neighborhood, including the twenty-third and twenty-fourth closest stars to the Sun. When added to eight other systems announced by this team and six by other groups since 2000, the known population of the Milky Way galaxy within 33 light-years (10 parsecs) of Earth has grown by 16 percent in just the past six years.<br /><br />The discoveries were made by a group called the Research Consortium on Nearby Stars (RECONS), which has been using small telescopes at the National Science Foundation's Cerro Tololo Inter-American Observatory (CTIO) in the Chilean Andes since 1999. These new results will appear in the December 2006 issue of the Astronomical Journal.<br /><br />"Our goal is to help complete the census of our local neighborhood and provide some statistical insights about the demographics of stars in our galaxy - their masses, their evolutionary states, and the frequency of multiple star systems," says RECONS Project Director Todd Henry of Georgia State University in Atlanta. "Due to their proximity, these systems are also excellent targets for exoplanet searches, and ultimately, for astrobiological studies of whether any planets that are found could support life."<br /><br />The 20 newly reported objects are all red dwarf stars, which now comprise 239 of the 348 known objects beyond our Solar System within the 10-parsec boundary of the RECONS survey. Thus, red dwarfs likely account for at least 69 percent of the Milky Way's residents.<br /><br />"Red dwarfs are among the faintest but most populous objects in the Milky Way," Henry explains. "Although you can't see a single one with the naked eye, there are swarms of them throughout the galaxy."<br /><br />The distances to these stars were measured via a classic trigonometric parallax technique using the 0.9-meter telescope at CTIO. The parallax technique for measuring the distance to a star takes advantage of the simple geometry of Earth's changing posi