[Previous] | [Session 60] | [Next]
E. V. Quintana (NASA Ames & University of Michigan), J. J. Lissauer, J. E. Chambers (NASA Ames), M. J. Duncan (Queen's University)
The recent detection of more than 70 planets outside of the Solar System has provided new insight into current theories on planet formation. Some of these extrasolar planets orbit stars which also possess a stellar companion, e.g., 16 Cygni B, Tau Bootis, and 55 Rho Cancri, confirming that planets can form in binary star systems. The radial velocity technique used to discover these planets are biased towards finding large (Jupiter-mass) planets, so the existence of Earth-sized planets in binary star systems, and the possibility of life on these planets, still remains observationally unconstrained. Since more than half of the stars have at least one stellar companion, we have developed new algorithms designed to model terrestrial planet growth around one or both stars in a binary system.
Herein, we examine planet formation around both components of the closest binary to the Sun, Alpha Centauri. Each integration begins with a `bimodal' mass distribution of several large embryos embedded in a disk of smaller planetesimals orbiting a star, and we follow the evolution of the accreting bodies for 200 Myr - 1 Gyr. Preliminary results suggest that systems with the initial inclination of the stellar companion above 45 degrees caused most of the mass in the disk to rapidly fall into the primary star. When the binary companion began at a lower inclination, however, the simulations typically produced 3 - 5 terrestrial planets within 2 AU of the primary star, and on roughly circular (e < 0.2) and roughly coplanar orbits.
The author(s) of this abstract have provided an email address for comments about the abstract: equintan@estrellas.arc.nasa.gov