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                                       “Planet formation and evolution:

            key processes to understand the diversity of planetary systems”

 

        Date:

    Download-files:

      Time:

Thursday, 19. April 2018

    Video-Recording for any system with MP4-support

   - Video.mp4  (ca.470 Mb)

 15:15 – 16:25

 

                                   

                                                      Alessandro Morbidelli

                                                     (Observatoire de la Cote d'Azur)

 

Abstract :

The discovery of a large number of extrasolar planets has demonstrated

that our own system is not "typical". Exo-planetary systems can be

very different from our own, and diverse from each other.

Understanding this diversity is a major goal of modern planetary

science.

 

The formation of planetary systems is not fully understood, but major

advances have been obtained in the last 10 years. New concepts have

been proposed, such as the streaming instability for the formation of

planetesimals and pebble accretion for the formation of protoplanets.

It is also now clear that planets forming in the proto-planetary disks

have to migrate during their accretion, if their mass exceeds a few

times the mass of Mars. Accretion and dynamical evolution are

therefore very coupled processes. This leads to complex evolutions,

very sensitive to initial conditions and fortuitous events, that are

the key to understand the observed diversity of planetary systems. The

early formation of Jupiter and its limited migration due to the

formation of Saturn are two fundamental ingredients that determined

the basic structure of the Solar System. The lack of early formation

of giant planets typically leads to the formation of super-Earth

planets on short period orbits. There is also evidence that the vast

majority of planetary systems become unstable after the removal of the

protoplanetary disk. The effects of this instability are very

different depending on the masses of the planets involved. Our Solar

System also experienced a global instability, but fortuitously our

giant planets did not develop large orbital eccentricities.

 

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