DPS 35th Meeting, 1-6 September 2003
Session 27. Planet and Satellite Origins II: Accretion, Terrestrial Planets
Oral, Chairs: F. Spahn and T. J. Ahrens, Thursday, September 4, 2003, 3:40-5:50pm, DeAnza I-II

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[27.09] Terrestrial Planet Formation Around Close Binary Stars

J. J. Lissauer (NASA Ames), E. V. Quintana (NASA Ames and Univ. Michigan)

Most stars reside in multiple star systems; however, virtually all models of planetary growth have assumed an isolated single star. Numerical simulations of the collapse of molecular cloud cores to form binary stars suggest that disks will form within such systems. Observations indirectly suggest disk material around one or both components within young binary star systems. If planets form at the right places within such circumstellar disks, they can remain in stable orbits within the binary star systems for eons. We are simulating the late stages of growth of terrestrial planets around close binary stars, using a new, ultrafast, symplectic integrator that we have developed for this purpose. The sum of the masses of the two stars is one solar mass, and the initial disk of planetary embryos is the same as that used for simulating the late stages of terrestrial planet growth within our Solar System and in the Alpha Centauri wide binary star system. Giant planets are included in the simulations, as they are in most simulations of the late stages of terrestrial planet accumulation in our Solar System. When the stars are of equal mass and travel on a circular orbit with semimajor axis of up to 0.1 AU, the planetary embryos grow into a system of terrestrial planets that is statistically identical to those formed about single stars, but a larger semimajor axis and/or a significantly eccentric binary orbit can lead to terrestrial planet systems that contain fewer planets and/or are more dynamically excited.

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Bulletin of the American Astronomical Society, 35 #4
© 2003. The American Astronomical Soceity.