Detached binaries in the Large Magellanic Cloud. A selection of binaries suitable for distance determination

TL;DR

This paper identifies 98 eclipsing binary systems in the Large Magellanic Cloud suitable for spectroscopic follow-up to accurately measure the galaxy's distance, highlighting systems with eccentric orbits and apsidal motion.

Contribution

It provides a carefully selected list of binaries with preliminary parameters, facilitating future spectroscopic studies for precise distance determination.

Findings

98 suitable binary systems identified

58 stars have eccentric orbits

14 systems show apsidal motion

Abstract

As a result of a careful selection of eclipsing binaries in the Large Magellanic Cloud using the OGLE-II photometric database, we present a list of 98 systems that are suitable targets for spectroscopic observations that would lead to the accurate determination of the distance to the LMC. For these systems we derive preliminary parameters combining the OGLE-II data with the photometry of MACHO and EROS surveys. In the selected sample, 58 stars have eccentric orbits. Among these stars we found fourteen systems showing apsidal motion. The data do not cover the whole apsidal motion cycle, but follow-up observations will allow detailed studies of these interesting objects.