Catalogue of wide binary, trinary and quaternary candidates from the Gaia data release 2 (region $\left\vert b\right\vert >25\,\deg$)

TL;DR

This paper presents a catalogue of over 900,000 binary, 5,000 trinary, and 30 quaternary star candidates identified from Gaia DR2 data using a novel statistical method focused on angular separation and proper motion collinearity.

Contribution

It introduces an optimized statistical approach for detecting multiple star systems in Gaia data, including a comprehensive catalogue of candidates with improved background estimation.

Findings

Catalogue includes 900,842 binaries, 5,282 trinaries, and 30 quaternaries.

Method effectively distinguishes multiple star candidates based on angular separation and proper motion.

Accurate background calculation enhances candidate selection reliability.

Abstract

The occurrence of multiple stars, dominantly binaries, is studied using the \textit{Gaia}-ESA DR2 catalogue. We apply the optimized statistical method that we previously developed for the analysis of 2D patterns. The field of stars is divided into a mosaic of small pieces, which represent a statistical set for analysis. Specifically, data input is represented by a grid of circles (events) with radius $0.02\,\deg$ covering the sky in the field of galactic latitude $\left\vert b\right\vert >25\,\deg$. The criteria for selecting candidates for multiple stars are based on two parameters: angular separation and collinearity of proper motion. Radial separation, due to limited accuracy, is used only as a weaker supplementary constraint. Due attention is paid to the accurate calculation of the background, which is a necessary input for evaluating the quality of the candidates. Our selection algorithm generates the catalogue of candidates: $900,842$ binaries, $5,282$ trinaries and $30$ quaternaries.