Binary Lenses in OGLE-III EWS Database. Seasons 2006--2008

TL;DR

This paper reports 27 new binary lens candidates from the OGLE-III database (2006-2008), expanding the sample to 78 stellar systems and 7 exoplanets, and analyzes their mass ratio distribution.

Contribution

It introduces a new set of binary lens candidates from OGLE-III data and provides insights into the distribution of stellar binary mass ratios, challenging previous findings.

Findings

Number of systems per log mass ratio increases with q

Binary systems occupy 0.03<q<1 range

There is a gap between stellar binaries and planets

Abstract

We present 27 binary lens candidates from OGLE-III Early Warning System database for the seasons 2006--2008. The candidates have been selected by visual light curves inspection. Our sample of binary lens events consists now of 78 stellar systems and 7 extrasolar planets of OGLE-III published elsewhere. Examining the distribution of stellar binaries we find that the number of systems per logarithmic mass ratio interval increases with mass ratio q, in contradiction with our previous findings. Stellar binaries belong to the region 0.03<q<1 and there is a gap between them and a separate population of planets.