Massive stars play a major role in the evolution of their host galaxies and serve as important
probes of the distant Universe. It has been established that the majority of massive stars …

Binary stars are as common as single stars. Binary stars are of immense importance to
astrophysicists because that they allow us to determine the masses of the stars independent …

We describe the discovery of a solar neighborhood (d= 468 pc) binary system with a main-
sequence sunlike star and a massive noninteracting black hole candidate. The spectral …

OB associations are unbound groups of young stars made prominent by their bright OB
members, and have long been thought to be the expanded remnants of dense star clusters …

Context. This is the second paper of a series on Galactic OB groups that uses astrometric
and photometric data from Gaia and spectral classifications from the Galactic O-Star …

Observational advances over the last decade have enabled high-resolution, interferometric
studies of forming multiple systems, statistical surveys of multiplicity in star-forming regions …

GRAVITY+ is the upgrade for GRAVITY and the Very Large Telescope Interferometer (VLTI)
with wide-separation fringe tracking, new adaptive optics, and laser guide stars on all four 8 …

Context. The study of the multiplicity of massive stars gives hints on their formation
processes and their evolutionary paths, which are still not fully understood. Large separation …

Context. Spectroscopic multiplicity surveys of O stars in young clusters and OB associations
have revealed that a large portion (∼ 70%) of these massive stars (M i> 15 M⊙) belong to …

Context. Massive stars are a key element for understanding the chemical and dynamical
evolution of galaxies. Stellar evolution is conditioned by many factors: Rotation, mass loss …