Related papers: The Dispersed Young Population in Orion
In this chapter we review the properties of the Orion outlying clouds at b < -21 degrees. These clouds are located far off the Orion giant molecular cloud complex and are in most cases small cometary-shaped clouds, with their head pointing…
The Orion Nebula Cluster (ONC) is the closest site of very young ($\sim$ 1 Myrs) massive star formation. The ONC hosts more than 1600 young and X-ray bright stars with masses ranging from $\sim$ 0.1 to 35 $M_\odot$. The Chandra HETGS Orion…
We present a study of the stellar populations and gas physical conditions in Circumnuclear Star Forming Regions (CNSFR) based on broad and narrow band photometry and spectrophotometric data, which have been analyzed with the use of…
Understanding the evolution and dissipation of protoplanetary disks are crucial in star and planet formation studies. We report the protoplanetary disk population in the nearby young $\sigma$ Orionis cluster (d$\sim$408 pc; age$\sim$1.8…
The distance to the Orion Nebula Cluster (ONC) is estimated using the rotational properties of its low-mass pre main-sequence (PMS) stars. Rotation periods, projected equatorial velocities and distance-dependent radius estimates are used to…
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…
The nearest site of massive star formation in Orion is dominated by the Trapezium subsystem, with its four OB stars and numerous companions. The question of how these stars came to be in such close proximity has implications for our…
If we want to understand the evolution from star clusters to the Galactic field star population, the Solar neighbourhood is an ideal place to start. It contains objects from dense, very young clusters to old and almost dissolved moving…
As a stellar group forms within its parent molecular cloud, new members first appear in the deep interior. These overcrowded stars continually diffuse outward to the cloud boundary, and even beyond. Observations have so far documented only…
OB associations, as an intermediate stage between Galactic clusters and field stars, play an important role in understanding the star formation process, early stellar evolution, and Galactic evolution. In this work, we construct a large…
A high number of embedded clusters is found in the Galaxy. Depending on the formation scenario, most of them can evolve to unbounded groups that are dissolved within a few tens of Myr. A systematic study of young stellar clusters showing…
I compare theoretical models of massive star formation with observations of the Orion Hot Core, which harbors one of the closest massive protostars. Although this region is complicated, many of its features (size, luminosity, accretion…
The nearby, young, extinction-free {\sigma} Orionis cluster is acknowledged as a cornerstone for studying the stellar and substellar formation and evolution, especially at very low masses. However, the relatively limited knowledge of…
We report on a high-spatial-resolution survey for binary stars in the periphery of the Orion Nebula Cluster, at 5 - 15 arcmin (0.65 - 2 pc) from the cluster center. We observed 228 stars with adaptive optics systems, in order to find…
Context: Field stars are not always single stars, but can often be found in bound double systems. Since binary frequencies in the birth places of stars, young embedded clusters, are sometimes even higher than on average the question arises…
We report the evidence that several low-mass stars (<~0.4 Msun) of the Orion and Upper Scorpius clusters have lithium abundances well below the interstellar value. Due to time-dependent depletion, our result implies stellar ages greater…
Some of the most massive globular clusters of our Milky Way, such as for example omega-Centauri, show a mixture of stellar populations spanning a few Gyr in age and 1.5 dex in metallicities. In contrast, standard formation scenarios predict…
We present spatial and kinematic correlation between the young stellar population and the cloud clumps in the Ophiuchus star-forming region. The stellar sample consists of known young objects at various evolutionary stages, taken from the…
The distribution of dust and molecular clouds in the direction of Galactic longitudes 132--158 deg and latitudes pm 12 deg is investigated. The maps of dust distribution in the area were plotted from the following surveys: the star counts…
The Eos cloud, recently discovered in the far ultraviolet via H$_2$ fluorescence, is one of the nearest known dark molecular clouds to the Sun, with a distance spanning from $\sim94-136$pc. However, with a mass…