Spotlight on Betelgeuse.Stars in the night sky-at least bright, nearby ones-need no longer appear as fuzzy points of lights in a heavenly picture. Taking advantage of the superior optics of the repaired Hubble Space Telescope Hubble Space Telescope (HST), the first large optical orbiting observatory. Built from 1978 to 1990 at a cost of $1.5 billion, the HST (named for astronomer E. P. Hubble) was expected to provide the clearest view yet obtained of the universe. , astronomers have for the first time directly imaged the face of a star other than our sun. Previous attempts to image stars have required intricate manipulation of multiple exposures. Researchers used Hubble's Faint Object Camera The Faint Object Camera (FOC) was a camera installed on the Hubble Space Telescope until 2002. It was replaced by the Advanced Camera for Surveys. The camera was built by Dornier GmbH and was funded by the European Space Agency. to zero in on the red supergiant Betelgeuse, a swollen star whose brightness and girth-1,000 times the diameter of the sun-have made it a favorite target for telescopes on the ground. The ultraviolet image taken with Hubble highlights the extended atmosphere of Betelgeuse and reveals a single large hot spot in the star's southwest quadrant. The spot has a diameter about 10 times that of Earth and a temperature of roughly 7,000 kelvins, 2,000 kelvins higher than its surroundings. In addition, there are smaller hot spots hot spots acute moist dermatitis. that speckle Speckle The generation of a random intensity distribution, called a speckle pattern, when light from a highly coherent source, such as a laser, is scattered by a rough surface or inhomogeneous medium. the sun "like German measles," says codiscoverer Andrea K. Dupree of the Harvard-Smithsonian Center for Astrophysics The Harvard-Smithsonian Center for Astrophysics (CfA) is located in Cambridge, Massachusetts. It consists of the Harvard College Observatory and the Smithsonian Astrophysical Observatory. The Center is located at 60 Garden Street. in Cambridge, Mass. She and Ronald L. Gilliland of the Space Telescope Science Institute The Space Telescope Science Institute (STScI) is the science operations center for the Hubble Space Telescope (HST; in orbit since 1990) and for the James Webb Space Telescope (JWST; scheduled to be launched in 2013). in Baltimore suggest two explanations for the hot spot on Betelgeuse. As in a bubbling cauldron, pulsations of the star may have carried hot gas to the surface and caused hot spots to appear and vanish. Alternatively, energetic magnetic fields within the star may have generated the heat that produced the spot. Images taken over the next few years to show the spot's motion may help determine the correct explanation. |
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