157 datasets found

Recent observations have challenged our understanding of rotational mixing in massive stars by revealing a population of fast-rotating objects with apparently normal surface...

We cross-match the Alma catalogue of OB stars with Gaia DR2 astrometry and photometry as a first step towards producing a clean sample of massive stars in the solar...

We study the motions inside 28 OB-associations with the use of Gaia DR2 proper motions. The average velocity dispersion calculated for 28 OB-associations including more than 20...

OB associations are the prime star-forming sites in galaxies. However, the detailed formation process of such stellar systems still remains a mystery. In this context,...

Citizen science has helped astronomers comb through large data sets to identify patterns and objects that are not easily found through automated processes. The Milky Way Project...

The infrared (IR) excess from OB stars is commonly considered to be a contribution from ionized stellar wind or circumstellar dust. With the newly published Large Sky Area...

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. They...

OB associations are important probes of recent star formation and Galactic structure. In this study, we focus on the Auriga constellation, an important region of star formation...

Historically, it has often been asserted that most stars form in compact clusters. In this scenario, present-day gravitationally-unbound OB associations are the result of the...

We have compiled a significantly updated and comprehensive census of massive stars in the nearby Cygnus OB2 association by gathering and homogenising data from across the...

The Hipparcos Catalogue (Cat. I/239) contains members of nearby OB associations brighter than 12th magnitude in V. However, membership lists are complete only to magnitude...

Recent work measuring the binary fraction of evolved red supergiants (RSGs) in the Magellanic Clouds points to a value between 15% and 30%, with the majority of the companions...

In this work, we report and discuss the detection of two distant diffuse stellar groups in the third Galactic quadrant. They are composed of young stars, with spectral types...

We derive projected rotational velocities (vsini) for a sample of 156 Galactic OB star members of 35 clusters, HII regions, and associations. The HeI lines at 4026, 4388, and...

A comprehensive census of the stellar content of the OB associations within 1 kpc from the Sun is presented, based on Hipparcos positions, proper motions, and parallaxes. It is...

Two regions in the Large Magellanic Cloud, centered at 05:11-66:08 (34B) and 05:27-72:15 (47B) have been searched for OB and supergiant stars. A catalogue of 312 stars is...

W40 is a heavily obscured bipolar HII region projected in the direction of the Aquila Rift and ionized by hot stars in a central, partly embedded cluster. The study of the...

As an increasing number of spectroscopic surveys become available, an automated approach to spectral classification becomes necessary. Due to the significance of the massive...

Luminous hot stars (M_Ks_<~0mag and Teff>~8000K) dominate the stellar energy input to the interstellar medium (ISM) throughout cosmological time, are used as laboratories...

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...