The Gaia NIR mission and the engagement of the Spanish Community

GaiaNIR Photometry and the Census of Unresolved Binaries

29 Jan 2026, 17:15

15m

Agencia Espacial Española (AEE) headquarters in Sevilla

IR Astrometry: big science questions (III). Chair: Josep Manel Carrasco

Speaker

Sagar Malhotra (IEEC-ICCUB)

Description

Precise Gaia astrometry and photometry have enabled large-scale studies of unresolved binaries across the Milky Way. However, most existing (spectro-)photometric techniques based solely on these data remain primarily sensitive to high mass-ratio systems (q ≳ 0.6). In a recent pathfinder study we demonstrated that incorporating near- and mid-infrared photometry—such as from 2MASS and WISE—significantly enhances the detectability of low-q binaries. The exquisite deep all-sky photometry from GaiaNIR will therefore be transformative, enabling a much more complete census of binary populations in the Galaxy and offering new constraints on the processes governing star formation and dynamical interactions.