Observations of H+ 3 in the Galactic diffuse interstellar medium have led to various
surprising results, including the conclusion that the cosmic-ray ionization rate (ζ 2) is about …

We present the first installment of a massive spectroscopic survey of Galactic O stars, based
on new, high signal-to-noise ratio, R∼ 2500 digital observations from both hemispheres …

We present the Automated Stellar Cluster Analysis package (ASteCA), a suit of tools
designed to fully automate the standard tests applied on stellar clusters to determine their …

Context. Multiplicity in massive stars is key to understanding the chemical and dynamical
evolution of galaxies. Among massive stars, those of O type play a crucial role due to their …

Context. The spectral classifications of the Galactic O-Star Spectroscopic Survey (GOSSS)
and the astrometric and photometric data from Gaia have significantly improved our ability to …

We propose a mixture model of open clusters (OCs) in color–magnitude diagrams (CMDs) to
measure the OC properties, including isochrone parameters (age, distance, metallicity, and …

Context. On the one hand, the second data release of the Gaia mission (Gaia DR2) has
opened a trove of astrometric and photometric data for Galactic clusters within a few …

Context. Multiplicity in massive stars is key to understanding the chemical and dynamical
evolution of galaxies. Among massive stars, those of O type play a crucial role due to their …

The star HD 193322 is a remarkable multiple system of massive stars that lies at the heart of
the cluster Collinder 419. Here we report on new spectroscopic observations and radial …

The most accurate parameters of star clusters are determined by analyzing colour-
magnitude diagrams (CMDs) constructed from their member stars. The recent study applying …