相关论文: The Nearest OB Association: Scorpius-Centaurus (Sc…
We present ALMA 880 micron continuum observations of 20 K and M-type stars in the Upper Scorpius OB association that are surrounded by protoplanetary disks. These data are used to measure the dust content in disks around low mass stars…
We exploited observational constraints on stars, gas and nucleosynthesis ashes for the closest region of recent massive-star formation, Scorpius-Centaurus OB2, and combined them with 3D hydrodynamical simulations, in order to address…
We present optical and near-infrared adaptive optics (AO) imaging and spectroscopy of 13 ultracool (>M6) companions to late-type stars (K7-M4.5), most of which have recently been identified as candidate members of nearby young moving groups…
Young low-mass stars of equal-mass exhibit a distribution of rotation periods. At the very early phases of stellar evolution, this distribution is set by the star-disc locking mechanism. The primordial disc lifetime and, consequently, the…
We attempt to determine the molecular composition of disks around young low-mass stars in the $\rho$ Oph region and to compare our results with a similar study performed in the Taurus-Auriga region. We used the IRAM 30 m telescope to…
SONYC -- Substellar Objects in Nearby Young Clusters -- is a survey program to investigate the frequency and properties of substellar objects in nearby star-forming regions. We present a new imaging and spectroscopic survey conducted in the…
The process that leads to the formation and early evolution of low-mass stars is in a broad sense well understood theoretically and carefully traced observationally. The largest uncertainties in this framework reside in the poorly known…
Stellar multiplicity properties have been studied for much of the range from the lowest to the highest stellar masses, but intermediate-mass stars from F-type to late A-type have received relatively little attention. Here we report on a…
Massive stars are recognized for their high degree of multiplicity, yet the mass ratio regime below 0.1 remains insufficiently explored. It is therefore unknown whether extremely low-mass (possibly substellar) companions can form and…
Young multiple star systems provide excellent testing grounds for theories of star formation and evolution. EPIC 203868608 was previously studied~\citep{David2016} as a triple star system in the Upper Scorpius OB association, but the…
The OB associations, which are fossil star formation regions, retain the end-products of the star formation process in an open, unobscured environment. Observations of the low mass stars in OB associations provide a far clearer picture of…
We present measurements of the orbital positions and flux ratios of 17 binary and triple systems in the Ophiuchus star forming region and the Upper Centaurus-Lupus cluster based on adaptive optics imaging at the Keck Observatory. We report…
Spectroscopic follow-up is a pre-requisite for studies of the formation and early evolution of brown dwarfs. Here we present IRTF/SpeX near-infrared spectroscopy of 30 candidate members of the young Upper Scorpius association, selected from…
In this review I discuss different theories of the formation of OB associations in the Milky Way, and provide the observational evidences in support of them. In fact, the second release of Gaia astrometric data (April 2018) is…
Sigma Orionis is an open cluster in the nearest giant star formation site - Orion. Its youth (3-5 Myr), low reddening, and relative vicinity make it an important benchmark cluster to study stellar and substellar formation and evolution.…
We present IRAC/MIPS Spitzer Space Telescope observations of the solar type and the low mass stellar population of the young (~5 Myr) Lambda Orionis cluster. Combining optical and 2MASS photometry, we identify 436 stars as probable members…
We study the temporal and spatial distribution of star formation rates in four well-studied star-forming regions in local molecular clouds(MCs): Taurus, Perseus, $\rho$ Ophiuchi, and Orion A. Using published mass and age estimates for young…
In a previous paper, using data from K2 Campaign 2, we identified 11 very low mass members of the $\rho$ Oph and Upper Scorpius star-forming region as having periodic photometric variability and phased light curves showing multiple scallops…
We are conducting a proper-motion survey for young brown dwarfs in the Taurus-Auriga molecular cloud based on the Pan-STARRS1 3$\pi$ Survey. Our search uses multi-band photometry and astrometry to select candidates, and is wider (370…
Evolutionary models of pre-main sequence stars remain largely uncalibrated, especially for masses below that of the Sun, making each new dynamical mass and radius measurement a valuable test of theoretical models. Stellar mass dependent…