Chasing a stellar blast.An exploding star recently discovered in a nearby galaxy may be a milestone in the study of type 1a supernovas supernova, a massive star in the latter stages of stellar evolution that suddenly contracts and then explodes, increasing its energy output as much as a billionfold. Supernovas are the principal distributors of heavy elements throughout the universe; all elements heavier than iron are produced in supernovas. Supernovas also are the principal heat source for interstellar matter and may be a source of cosmic rays.. In this past decade, astronomers have used these stellar explosions, produced when an elderly star called a white dwarf white dwarf, in astronomy, a type of star that is abnormally faint for its white-hot temperature (see mass-luminosity relation). Typically, a white dwarf star has the mass of the sun and the radius of the earth but does not emit enough light or other radiation to be easily detected. The existence of white dwarfs is intimately connected with stellar evolution. A white dwarf is the hot core of a star, left over after the star uses up its nuclear fuel and dies. blows up, to determine that the universe is expanding at an accelerating rate. But despite the importance of these events, no one knows exactly how white dwarfs explode. Because the newfound supernova, dubbed SN 2006X, erupted in a nearby, highly studied galaxy, it could provide a wealth of information. Amateur astronomers in Japan and Italy independently found the supernova on Feb. 4. At the time of the discovery, the supernova was only one-thousandth as bright as its home galaxy, Messier 100, which lies about 60 million light-years from Earth. But over the next 2 weeks, the supernova's glow increased 25-fold. Using the Very Large Telescope in Paranal, Chile, Dietrich Baade of the European Southern Observatory European Southern Observatory (ESO), an intergovernmental organization for astronomical research with headquarters in Garching, near Munich, Germany. The ESO began in 1962 as a consortium among Belgium, Denmark, France, Germany, the Netherlands, and Sweden. Great Britain, Italy, Portugal, and Sweden subsequently joined. The ESO operates two major observatories in the Atacama desert, Chile. in Garching, Germany, and his colleagues have been measuring SN 2006X'S brightness since its discovery. They announced their findings in a Feb. 23 press release. |
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