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  • mahtezcatpoc
    ... http://news.yahoo.com/s/space/20081125/sc_space/anotherextrasolarplane tpossiblyimaged Another Extrasolar Planet Possibly Imaged Jeanna Bryner Senior
    Message 1 of 2 , Nov 28, 2008
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      > Another Extrasolar Planet Possibly Imaged - Yahoo! News
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      http://news.yahoo.com/s/space/20081125/sc_space/anotherextrasolarplane
      tpossiblyimaged


      Another Extrasolar Planet Possibly Imaged

      Jeanna Bryner
      Senior Writer
      SPACE.com

      – Tue Nov 25, 8:35 am ET

      Astronomers say they have directly imaged a giant exoplanet orbiting
      its parent star. The announcement comes on the heels of two other
      reports this month of direct images of planets beyond our solar
      system.


      The new infrared image shows the object as a speck of light near the
      star Beta Pictoris, which is 70 light-years from Earth, toward the
      constellation Pictor.


      "We cannot yet rule out definitively, however, that the candidate
      companion could be a foreground or background object," said study
      team member Gael Chauvin of Grenoble Observatory in France. "To
      eliminate this very small possibility, we will need to make new
      observations that confirm the nature of the discovery."


      Chauvin and other French astronomers discovered the candidate planet
      using the European Southern Observatory's (ESO) Very Large Telescope.
      The possible planet is estimated to weigh about eight times the mass
      of Jupiter with an orbit of eight astronomical units (AU) from its
      star, where one AU is the average Earth-sun distance.


      Astrophysicist Sara Seager of MIT, who was not involved in the latest
      discovery, said while the possibility is exciting, another more
      convincing image of the object is in order. "We want to make sure
      it's moving together with the star," Seager said.


      Another image would show whether the star is moving at a different
      speed relative to this object and other background objects or if the
      star and planet are moving together (which would help to confirm this
      is indeed a planet).


      Astronomers had thought a planet could be responsible for
      irregularities seen in the debris disk, first imaged in 1994,
      surrounding Beta Pictoris. As a planet treks around its star, the
      planet jostles and tugs on pieces of dust and debris, shaping the
      disk.


      "Beta Pic has been teasing astronomers for the past two decades with
      hints of an orbiting planet," said University of California,
      Berkeley, astronomer Paul Kalas, who was not directly involved with
      the study. Kalas led a team of astronomers who reported this month
      the first visible-light snapshot of a single-planet system around the
      star Fomalhaut.


      The researchers say the object does explain the warped disk. "The
      candidate companion has exactly the mass and distance from its host
      star needed to explain all the disk's properties," said team leader
      Anne-Marie Lagrange of the Grenoble Observatory.


      The team tried to rule out other non-planet possibilities. For
      instance, they looked at images taken by the Hubble Space Telescope
      of the system, which would likely reveal background and foreground
      objects.


      They also used three independent detection methods to rule out the
      possibility that the point source of light was just an artifact of
      the observing instrument.


      "Overall, this is an exciting discovery that could be verified in
      just a few weeks time since Beta Pictoris is a bright star visible
      during the winter months," Kalas told SPACE.com.


      Actually, Lagrange said the planet might not be visible with their
      instruments currently, because of the inclination of the orbit and
      how it is aligned. So from our perspective on Earth, the planet could
      travel too close to its star to be visible.


      The discovery will be detailed in a forthcoming letter to the editor
      in the journal Astronomy and Astrophysics.
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