Extrasolar Planets

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Extrasolar Planets

• Presented by David Miranda

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Extrasolar Planets History

• The first extrasolar planet was discovered around
  a pulsar in 1991.
• The first extrasolar planet to orbit a star was
  discovered in 1995.
• The first direct detection of an extrasolar
  planet was just made in 2005.
• There are have been 140 extrasolar planets
  discovered.

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How are extrasolar planets detected?

• Prior to this year the detection of extrasolar
  planets was done indirectly.
• Instead of looking for the planets themselves
  (which emit less light than its parent star)
  Astronomers searched for a wobble in the motion
  of the star.

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How are extrasolar planets detected?

• This wobble occurs because when the planet orbits
  a star the planet exerts a gravitational
  attraction on the star.
• This gravitational attraction causes the star to
  slightly orbit in a small circle, which through
  the telescope looks like the star is wobbling.

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How are extrasolar planets detected?

• This effect is very small and can not be seen
  visually but can be detected through the Doppler
  Effect.
• The Doppler Effect is the change in the
  appearance of light waves from an object that is
  moving away from or toward the viewer.

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How are extrasolar planets detected?

• Another method used by astronomers is the
  transit method.
• This method involves detecting the dimming and
  blinking of a star when a planets passes in front
  of it.

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New Techniques

• In 2005 a new technique using NASAs Spitzer
  Space Telescope discovered two new extrasolar
  planets (TrES-1 and HD 209458b)
• This new technique involved detecting the
  infrared light emitted by the planets.

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TrES-1

• Discovered by the Harvard-Smithsonian Center for
  Astrophysics research group led by David
  Charbonneau.
• Planet is slightly less massive than Jupiter.
• About 500 light-years from Earth.

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HD 209458b

• Discovered by NASAs Goddard Space Flight Center
  research group led by Drake Deming.
• Slightly less massive than Jupiter.
• Slightly larger than Jupiter.
• About 150 light years from Earth.
• Research Paper published in Nature

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First photo of extrasolar planet?

• Photograph taken by the Hubble Near Infrared
  Camera of a brown dwarf star and possibly a giant
  planet orbiting it. Not yet confirmed.

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References

• http//www.space.com/scienceastronomy/030522_exopl
  anet_direct.html
• http//astron.berkeley.edu/gmarcy/encarta.html
• http//hubblesite.org/newscenter/newsdesk/archive/
  releases/2005/03/image/a
• http//www.newkerala.com/news-daily/news/features.
  php?actionfullnewsid89965