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E. V. Quintana (NASA Ames), F. C. Adams (University of Michigan), J. J. Lissauer (NASA Ames), J. E. Chambers (Carnegie/DTM)
More than 90 numerical simulations have been performed to examine the final stages of terrestrial planet formation around one component of a main-sequence binary star system. Using essentially the same circumstellar disk mass distribution that was used previously in simulations of planetary accretion in the \alpha Centauri binary (Quintana et al. 2002, ApJ, 576, 982), we explore a wider parameter space for binary star systems. This study focuses on equal mass stars with M\ast = 0.5 M\odot or 1.0 M\odot; the stellar orbital parameters are varied such that the binary periastron qB = 5, 7.5, or 10 AU.
When the binary periastron qB \gtrsim 10 AU, terrestrial planets can form over essentially the entire range of orbits allowed for single stars, although fewer planets tend to form within binary systems with high eccentricities. As the binary periastron decreases, the radial extent of the terrestrial planet systems decreases accordingly. When the periastron decreases to 5 AU, the formation of Earth-like planets near a = 1 AU is compromised. The stellar companion determines an outer boundary for the terrestrial region, but does not prevent the formation of terrestrial planets. Since more than half of all binary stars have periastron qB \gtrsim 7 AU, terrestrial planet formation within binary star systems may be more common than previously thought.
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Bulletin of the American Astronomical Society, 37 #2
© 2005. The American Astronomical Soceity.