HR: 1340h
AN: P33A-0995    [Abstracts]
TI: Terrestrial Planet Formation Around Close Binary Star Systems
AU: * Quintana, E V
EM: equintan@pollack.arc.nasa.gov
AF: NASA Ames Research Center, MS 245-3 , Moffett Field, CA 94035 United States
AU: Lissauer, J J
EM: jlissauer@mail.arc.nasa.gov
AF: NASA Ames Research Center, MS 245-3 , Moffett Field, CA 94035 United States
AB: More than half of all main sequence stars, and an even larger fraction of pre-main sequence stars, reside in multiple star systems. Virtually all previous models of planet formation, however, have assumed an isolated single star. Observations indirectly suggest disk material around one or both components of young binary star systems. If planets form at the right places within such disks, they can remain dynamically stable for very long times. We are numerically simulating the late stages of terrestrial planet growth around close binary star systems using a new, ultrafast, symplectic integrator that we have developed for this purpose. Binary systems with stellar separations $a_B \leq$ 0.4 AU are examined, which comprise $\sim$ 10% of main-sequence binary star systems. The sum of the masses of the two stars is 1 solar mass, and the initial disk of planetary embryos is the same as that used for simulating the late stages of terrestrial planet formation within our Solar System and around each star in the $\alpha$ Centauri AB wide binary system. Giant planets are included, as they are in most simulations of terrestrial planet growth around the Sun. When the stars are of equal mass and travel on a circular orbit with $a_B$ of up to 0.1 AU, the planetary embryos grow into a system of terrestrial planets that is statistically consistent with those formed about single stars. 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.
DE: 5400 PLANETOLOGY: SOLID SURFACE PLANETS
DE: 5450 Orbital and rotational dynamics
DE: 5455 Origin and evolution
DE: 6200 PLANETOLOGY: SOLAR SYSTEM OBJECTS (New field)
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting