Variability survey in the CoRoT SRa01 field: Implications of eclipsing binary distribution on cluster formation in NGC 2264

TL;DR

This study analyzes the distribution of variable stars, especially eclipsing binaries, in the NGC 2264 cluster using CoRoT data, revealing insights into cluster formation and binary orientation.

Contribution

It provides the first comprehensive variability survey of the CoRoT SRa01 field and uncovers the spatial distribution and orientation of eclipsing binaries within NGC 2264.

Findings

920 new variable stars discovered

Higher frequency of Algol binaries toward cluster center

Binary orbital planes are nearly edge-on within the cluster

Abstract

Time-series photometry of the CoRoT field SRa01 was carried out with the Berlin Exoplanet Search Telescope II (BEST II) in 2008/2009. A total of 1,161 variable stars were detected, of which 241 were previously known and 920 are newly found. Several new, variable young stellar objects have been discovered. The study of the spatial distribution of eclipsing binaries revealed the higher relative frequency of Algols toward the center of the young open cluster NGC 2264. In general Algol frequency obeys an isotropic distribution of their angular momentum vectors, except inside the cluster, where a specific orientation of the inclinations is the case. We suggest that we see the orbital plane of the binaries almost edge-on.