Abstract

The Occurrence of Wide-Orbit Planets in Binary Star Systems

Benjamin Zuckerman (UCLA)

The occurrence of planets in binary star systems has been investigated via a variety of techniques that sample a wide range of semimajor axes, but with a preponderance of such results applicable to planets with semimajor axes less than a few AU. We utilize a new method -- the presence or absence of heavy elements in the atmospheres of white dwarf stars -- to elucidate the frequency in main sequence binary star systems of planets with semimajor axes greater than a few AU. We consider only binaries where a putative planetary system orbits one member (no circumbinary planets). For main sequence binaries where the primary star is of spectral type A or F, data in the published literature suggests that the existence of a secondary star with a semimajor axis less than about 1000 AU suppresses the formation and/or long term stability of an extended planetary system around the primary. For these spectral types and initial semimajor axis of about 1000 AU or greater, extended planetary systems appear to be as common around stars in binary systems as they are around single stars.

Mode of presentation: oral