Proper motions and brown dwarfs with the VVV survey

TL;DR

The VVV survey has enabled the discovery and characterization of brown dwarfs and low-mass companions in the crowded Galactic center, leveraging multi-epoch near-infrared data for precise motions and variability analysis.

Contribution

This work demonstrates the first brown dwarfs identified towards the Galactic center using the VVV survey, highlighting its synergy with Gaia for future astrometric studies.

Findings

Discovered brown dwarfs in the Galactic center region.

Achieved precise parallaxes and variability constraints.

Projected discovery of over a hundred more brown dwarfs.

Abstract

The Vista Variables in the V\'ia L\'actea survey (VVV) is a near-IR ESO public survey devoted to study the Galactic bulge and southern inner disk covering 560 deg$^2$ on the sky. This multi-epoch and multi-wavelength survey has helped to discover the first brown dwarfs towards the Galactic center, one of the most crowded areas in the sky, and several low mass companions to known nearby stars. The multi-epoch information has allowed us to calculate precise parallaxes, and put some constraints on the long-term variability of these objects. We expect to discover above a hundred more brown dwarfs. The VVV survey makes a great synergy with the Gaia mission, as both will observe for a few years the same fields at different wavelengths, and as VVV is more sensitive to very red objects such as brown dwarfs, VVV might provide unique candidates to follow up eventual astrometric microlensing events thank to the exquisite astrometric precision of the Gaia mission.