The dispersal of protoplanetary disks around binary stars

TL;DR

This paper models the evolution of disks around binary stars, highlighting the role of photoevaporation in disk dispersal, and suggests that close binaries may frequently host circumbinary planets.

Contribution

It introduces models showing how photoevaporation influences disk lifetimes around binary stars, providing new insights into planet formation in such systems.

Findings

Photoevaporation rate is the primary factor in disk dispersal.

Disk lifetimes sharply increase for binaries with separations less than 0.3-1 AU.

Current observations limit ongoing photoevaporation rates to below 1e-9 M_sun/yr.

Abstract

I present models of disk evolution around young binary stars. I show that the primary factor in determining circumbinary disk lifetimes is the rate of disk photoevaporation. I also find that photoevaporative clearing leaves a signature on the distribution of circumbinary disk lifetimes, with a sharp increase in disk lifetimes for binary separations a<~0.3-1AU. Observations of young binary stars can therefore be used to test models of disk evolution, and I show that current data set a strong upper limit to the rate of on-going photoevaporation (<1e-9 M_sun/yr). Finally I discuss the implications of these results for planet formation, and suggest that circumbinary planets around close (a<~1AU) binaries should be relatively common.