Saturn Forms by Core Accretion in 3.4 Myr

Authors: Sarah E. Dodson-Robinson (1), Peter Bodenheimer (2), Gregory Laughlin (2), Karen Willacy (3), Neal J. Turner (3), C. A. Beichman (1) ((1) NASA Exoplanet Science Institute, (2) UCO/Lick Observatory, (3) JPL)

(Submitted on 1 Oct 2008)

Abstract: We present two new in situ core accretion simulations of Saturn with planet formation timescales of 3.37 Myr (model S0) and 3.48 Myr (model S1), consistent with observed protostellar disk lifetimes.

In model S0, we assume rapid grain settling reduces opacity due to grains from full interstellar values (Podolak 2003). In model S1, we do not invoke grain settling, instead assigning full interstellar opacities to grains in the envelope.

Surprisingly, the two models produce nearly identical formation timescales and core/atmosphere mass ratios. We therefore observe a new manifestation of core accretion theory: at large heliocentric distances, the solid core growth rate (limited by Keplerian orbital velocity) controls the planet formation timescale. We argue that this paradigm should apply to Uranus and Neptune as well.

Comments: 4 pages, including 1 figure, submitted to ApJ Letters

Subjects: Astrophysics (astro-ph)

Cite as: arXiv:0810.0288v1 [astro-ph]

Submission history

From: Sarah Dodson-Robinson [view email]

[v1] Wed, 1 Oct 2008 20:59:18 GMT (26kb)

http://arxiv.org/abs/0810.0288