Jack J. Lissauer
Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris
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| « How extreme can planetary systems be? » |
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Jack J. Lissauer |
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The first system of extrasolar planets was found in orbit about a pulsar. The next was a giant planet in a 4 day orbit, and following that a more massive giant in an eccentric orbit. These types of planetary systems were not expected prior to being found. What else is out there, in our galaxy? Dynamical stability (for a large number of orbits) is a requirement, but beyond that what restrictions are there? For instance, a nearly coplanar system analogous to our solar system but with planets alternating between prograde and retrograde orbits with increasing distance from star would be stable but not plausible. A pure lead planet could survive, but how could such a planet form? Various speculations will be discussed, with a focus on 'predictions' that are likely to be observationally testable within the next decade or two.
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vendredi 22 juin 2007 - 11:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |