Related papers: On the origin of field O-type stars
The past two decades have seen dramatic progress in our knowledge of the population of young stars of age $< 200\,$Myr that lie within $150\,$pc of the Sun. These nearby, young stars, most of which are found in loose, comoving groups,…
We present a catalog of near-infrared surveys of young (<= a few 10^6 yr) stellar groups and clusters within 1 kpc from the Sun, based on an extensive search of the literature from the past ten years. We find 143 surveys from 69 published…
Open clusters (OCs) are infrequent survivors of embedded clusters gestated in molecular clouds. Up to now, little is known about the initial conditions for the formation of OCs. Here, we studied this issue using high-precision astrometric…
The physical nature of a series of 20 new open clusters is confirmed employing existing data on putative star members, mainly from second Gaia Data Release (DR2). The clusters were discovered as overdensities of stars by visual inspection…
We use the open clusters (OCs) with known parameters available in the WEBDA database and in recently published papers to derive properties related to the disk structure. The sample totals 654 OCs, consisting basically of Trumpler types I to…
We investigate the distribution of bright main sequence stars near the northern edge of the M33 disk. Clustering on sub-kpc scales is seen among stars with ages near 10 Myr, and two large star-forming complexes are identified. Similar…
We conducted a survey of open clusters within 1 kpc from the Sun using the astrometric and photometric data of the Gaia Data Release 2. We found 655 cluster candidates by visual inspection of the stellar distributions in proper motion space…
The Sun likely formed as part of a group of stars. A close stellar flyby by one of the solar siblings is probably responsible for the sharp outer edge in the solar system`s mass distribution. The frequency of such close flybys can be used…
The apparent lack of massive O-type stars near the zero-age main sequence (at ages < 2 Myr) is a topic widely discussed. Different explanations for this elusive detection have been proposed, but no firm conclusions have been reached yet. We…
We have collected high-dispersion echelle spectra of red giant members in the twelve open clusters (OCs) and derived stellar parameters and chemical abundances for 26 species by either line equivalent widths or synthetic spectrum analyses.…
The new census of massive stars in the Carina nebula reveals the presence of 54 apparently single O-type stars in the Car OB1 association, an extremely active star-forming region which hosts some of the most luminous stars of the Milky Way.…
The star forming region of the Orion Nebula (ONC) is ideal to study the stellar dynamics of young stars in a clustered environment. Using Gaia DR2 we search for the pre-main sequence stars with unusually high proper motions that may be…
The recent discoveries of nearby star clusters and associations within a few hundred pc of the Sun, as well as the order of magnitude difference in the formation rates of the embedded and open cluster populations, suggests that additional…
An unsettled question concerning the formation and distribution of massive stars is whether they must be born in massive clusters and, if found in less dense environments, whether they must have migrated there. With the advent of wide-area…
The recent catalog of spectral types of Galactic O-type stars by Mai'z-Apella'niz et al. has been used to study the differences between the frequencies of various subtypes of O-type stars in the field, in OB associations and among runaway…
Stars are born within dense clumps of giant molecular clouds, constituting young stellar agglomerates known as embedded clusters, which only evolve into bound open clusters under special conditions. We statistically study all embedded…
We present results of a study of the galactic open cluster population based on the all-sky catalogue ASCC-2.5 (I/280A) compiled from Tycho-2, Hipparcos and other catalogues. The sample of optical clusters from ASCC-2.5 is complete up to…
The ability of HST to resolve objects ten times smaller than possible from the ground has rejuvenated the study of young star clusters. A recurrent morphological theme found in nearby resolved sytems is the observation of young (typically 1…
We present results of the first extensive and deep CCD photometric survey carried out in the field of the open cluster Trumpler 27, an object in the constellation of Sagittarius not far from the Galaxy center. We look for young stars clumps…
Traditionally runaway stars are O and B type stars with large peculiar velocities.We want to extend this definition to young stars (up to ~50 Myr) of any spectral type and identify those present in the Hipparcos catalogue applying different…