Dynamical Simulations of HD 69830 system

View previous topic View next topic Go down

Dynamical Simulations of HD 69830 system

Post by Sirius_Alpha on 15th December 2008, 9:09 pm

Dynamical Simulations of the Planetary System HD69830
http://arxiv.org/abs/0812.2475

Abstract wrote:HD 69830 exhibits radial velocity variations attributed to three planets as well as infrared emission attributed to a warm debris disk. Previous studies have developed models for the planet migration and mass growth (Alibert et al. 2006) and the replenishment of warm grains (Wyatt et al. 2007). We perform n-body integrations in order to explore the implications of these models for: 1) the excitation of planetary eccentricity, 2) the accretion and clearing of a putative planetesimal disk, 3) the distribution of planetesimal orbits following migration, and 4) the implications for the origin of the IR emission. We find that: i) It is not possible to explain the observed planetary eccentricities (e~0.1) purely as the result of planetary perturbations during migration unless the planetary system is nearly face-on. ii) The rate of accretion of planetesimals onto planets in our n-body simulations is significantly different to that assumed in the semi-analytic models, suggesting that one cannot successfully treat planetesimal accretion in the simplified manner of Alibert et al. (2006). iii) Eccentricity damping of planetesimals does not act as an insurmountable obstacle to the existence of an excited eccentric disk: All simulations result in at least 25 Earth-masses of material remaining bound in the region ~1-9 AU, even after all three planets have migrated through the region. iv) Gas drag works to size-sort the planetesimals, with the largest bodies preferentially occupying the highest eccentricity and longest-lived orbits. Further work will be required to understand whether these eccentricity distributions are high enough to explain the level of dust emission observed despite mass loss via steady state collisional evolution. [abridged]

_________________
Caps Lock: Cruise control for 'Cool'!
avatar
Sirius_Alpha
Admin
Admin

Number of posts : 3435
Location : Earth
Registration date : 2008-04-06

View user profile http://solar-flux.forumandco.com/

Back to top Go down

Re: Dynamical Simulations of HD 69830 system

Post by Lazarus on 16th December 2008, 7:24 am

Well it would be amusing if the first "triple-Neptunes" system turned out to be a bunch of Jovians, though IIRC there aren't many planets around Saturn's mass compared to either Jupiter-mass or Neptune-mass planets.
avatar
Lazarus
dG star
dG star

Number of posts : 2797
Registration date : 2008-06-12

View user profile

Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum