Search for new single-lined binary system (SB1) candidates using Gaia DR3 and GALAH DR3 data

english

2026

volume 13, issue 1

binary systems   GAIA catalogues   GALAH survey   spectroscopic binaries   spectroscopic sky surveys   stars

Univerza v Ljubljani, Fakulteta za matematiko in fiziko
(Obvezni izvod spletne publikacije)

Stars, essential to our understanding of the universe, often exist in binary systems, where two stars orbit each other. Among these, single-lined spectroscopic binaries (SB1) involve one star that cannot be directly seen, and is instead identified through periodic Doppler shifts in the spectrum of its companion. This paper cross-matches Gaia Data Release 3 (Gaia DR3) spectroscopic data with GALAH Data Release 3 (GALAH DR3) spectroscopic data (note that at the time of this study, DR4 was not yet publicly available) to identify potential SB1 candidates. From GALAH, 34 631 objects with more than one radial velocity (RV) measurement are selected, resulting in 9 148 SB1 candidates. When data from the Gaia DR3 catalog are incorporated, the number of objects increases to 502 377, and the number of SB1 candidates rises to 35 537. However, Gaia provides only a single additional RV measurement per star, which limits the number of newly identifiable SB1 systems. Still, this represents the largest catalog of SB1 candidates to date. Based on the data, it is clear that a significant portion of stars are likely SB1 candidates, but precise measurements are necessary for accurate identification. By analyzing key parameters like mass, temperature, luminosity, surface gravity and chemical composition, the study aims to better understand the properties and dynamics of these systems.

23.09.2026