Giant Planet Formation and Wobbling Stars

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

The standard model of giant planet formation requires the accumulation of a ~ 10 M_oplus ice/rock core that can accrete hydrodynamically an envelope of H and He gas prior to the removal of the solar nebula. Recent models of Jovian planet interiors have revised downward considerably their estimated core masses, removing much of the rationale for the core accretion model. This trend toward a more solar-like composition for Jupiter and Saturn suggests that a reappraisal of an alternative mechanism is appropriate, giant gaseous protoplanet formation (GGPP) by gravitational instability of an intermediate mass ( ~ 0.14 M_sun) solar nebula. Three dimensional hydrodynamical models of the evolution of such a disk, starting from a realistic, non-power-law, radial thermal profile, have shown that disks with Toomre Q stability parameters of ~ 1 can break-up into multiple-Jupiter-mass GGPPs within a few hundred years, regardless of the thermodynamics of the instability (1997, Science, 276, 1836-1839). These models fixed the location of the solar-mass protostar at the center of the disk, which discouraged the growth of m = 1 modes. New models which allow the central protostar to wobble back and forth to preserve the center of mass of the star-disk system show that the resulting preferential excitation of m = 1 modes leads to the formation of two GGPPs, at 5 AU and 10 AU from the central star, similar to the distances of Jupiter and Saturn. Giant planets could only form by the GGPP mechanism in regions of the disk with sufficiently cool temperatures, however, so like the core accretion mechanism, the GGPP mechanism offers no easy explanation for the formation in situ of the hot Jupiters (e.g., 51 Pegasi B); in either case, post-formational orbital migration must be invoked to explain the present location of hot Jupiters. Jupiter and Saturn, on the other hand, apparently experienced little or no orbital migration.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Giant Planet Formation and Wobbling Stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Giant Planet Formation and Wobbling Stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Giant Planet Formation and Wobbling Stars will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1173649

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.