Speaker
Description
Exoplanets have been discovered in binary star systems orbiting around one of the stars in a circumstellar orbit or around the binary in a circumbinary orbit. In this talk, I will discuss the dynamics of both types of planets and the constraints that they place on the formation and evolution of planetary systems. For two of the tightest binaries with circumstellar planets, HD 59686 and nu Octantis, dynamical fitting of the radial velocity data and stability analysis show that the planets are most likely on retrograde orbits, and high-resolution imaging has allowed us to determine the nature of the secondary stars. The orbits of circumbinary planets can be significantly non-Keplerian, and the free eccentricity is determined by dynamical processes during the formation and/or subsequent evolution of the planets. We have examined all known circumbinary planets and determined their free eccentricities. We find that circumbinary planets exhibit systematically low free eccentricities compared to the eccentricities of planets around single stars.
