The dynamical fate of wide binaries in the solar neighborhood

The authors explore the evolution of wide binaries in the solar neighborhood driven by perturbations from passing stars and giant molecular clouds. They develop a Monte Carlo technique which exploits the fact that most perturbers encounter a wide binary at large impact parameter so that their cumulative effect may be described as a diffusion process. The rare catastrophic encounters are treated individually. It is shown that the effects of stars and clouds interact in disrupting a binary. Two possible evolutionary scenarios for the population of wide binaries are studied: (1) a "burst" model, in which a particular distribution of binaries in semimajor axis is created initially and evolved; and (2) a "continuous creation" model, in which a population is continuously created with a particular distribution in semimajor axes. The authors also address the period stability and lifetime of the proposed solar companion.