RAS/ESO: Turning Planetary Theory Upside Down

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bystander
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RAS/ESO: Turning Planetary Theory Upside Down

Post by bystander » Tue Apr 13, 2010 4:26 pm

Turning Planetary Theory Upside Down
Royal Astronomical Society Press Release
(with the European Southern Observatory)
RAS PN 10/25 (NAM 10) 13-Apr-2010
eso1016 Science Release 12 Apr 2010
The discovery of nine new transiting exoplanets is announced today at the RAS National Astronomy Meeting (NAM2010). When these new results were combined with earlier observations of transiting exoplanets astronomers were surprised to find that six out of a larger sample of 27 were found to be orbiting in the opposite direction to the rotation of their host star — the exact reverse of what is seen in our own Solar System. The new discoveries provide an unexpected and serious challenge to current theories of planet formation. They also suggest that systems with exoplanets of the type known as hot Jupiters are unlikely to contain Earth-like planets.
Dropping a Bomb About Exoplanets
Universe Today - 13 Apr 2010
Not all exoplanets are created equal, and new discoveries about the orbits of newly found extra solar planets could challenge the current theories of planet formation. The discoveries also suggest that systems with exoplanets of the type known as hot Jupiters are unlikely to contain Earth-like planets. “This is a real bomb we are dropping into the field of exoplanets,” said Amaury Triaud, a PhD student at the Geneva Observatory who led an observational campaign from several observatories.

Six exoplanets out of twenty-seven were found to be orbiting in the opposite direction to the rotation of their host star — the exact reverse of what is seen in our own Solar System. The team announced the discovery of nine new planets orbiting other stars, and combined their results with earlier observations. Besides the surprising abundance of retrograde orbits, the astronomers also found that more than half of all the so-called "hot Jupiters" in their survey have orbits that are misaligned with the rotation axis of their parent stars.
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Re: RAS/ESO: Turning Planetary Theory Upside Down

Post by neufer » Tue Apr 13, 2010 7:11 pm

If these planets were all observed by the transit method then they are likely to be those planets nearest to their parent stars and, hence, the ones with the least angular momentum. With an inclination of 6.34° to Invariable plane Sol's Mercury is not terribly representative of the angular momentum of the solar system as a whole. Violent interactions such as those that generated the earth's moon or that tipped Uranus on it's side could well have generated retrograde inner planets.
Art Neuendorffer