Related papers: M Stars in the TW Hya Association: Stellar X-rays …
Exoplanet demographic surveys have revealed that close-in (${\lesssim}$1 au) small planets orbiting stars in the Milky Way's thick disk are ${\sim}50\%$ less abundant than those orbiting stars in the Galactic thin disk. One key difference…
We discuss the properties of several circumstellar debris disk systems imaged with the Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer in a survey of young stars with known far-IR excesses. These dusty disks…
Circumstellar debris disks are important because of their connection to planetary systems. An efficient way to identify these systems is through their infrared excess. Most studies so far concentrated on early-type or solar-type stars, but…
We discuss a hydrodynamical model for the dispersal of protoplanetary discs around young, low mass (<1.5 M_sun) stars by photoevaporation from the central object's energetic radiation, which considers the far-ultraviolet as well as the…
We present high resolution (0.3" = 16 AU), high signal-to-noise ratio Submillimeter Array observations of the 870 microns (345 GHz) continuum and CO J=3--2 line emission from the protoplanetary disk around TW Hya. Using continuum and line…
Context. The intense X-ray and UV emission of some active M stars has raised questions about the habitability of planets around M-type stars. Aims. We aim to determine the unbiased distribution of X-ray luminosities in complete,…
We analyzed a long duration flare observed in a serendipitous XMM-Newton detection of the M star CD-39 7717B (TWA 11B), member of the young stellar association TW Hya (~ 8 Myr). Only the rise phase (with a duration of ~ 35 ks) and possibly…
The XMM-Newton Extended Survey of the TMC (XEST) is a large program designed to systematically investigate the X-ray properties of young stellar/substellar objects in the TMC. In particular, the area surveyed by 15 XMM-Newton pointings (of…
Based on archival {\it Chandra} data, we have carried out an X-ray survey of 69, or nearly half the known population of, Milky Way globular clusters (GCs), focusing on weak X-ray sources, mainly cataclysmic variables (CVs) and coronally…
The high-energy emission from low-mass stars is mediated by the magnetic dynamo. Although the mechanisms by which fully convective stars generate large-scale magnetic fields are not well understood, it is clear that, as for solar-type…
Long-term homogeneous photometry for 35 classical T Tauri stars (cTTS) in the Taurus-Auriga star-forming region (Tau-Aur SFR) has been analyzed. Reliable effective temperatures, interstellar extinctions, luminosities, radii, masses, and…
Recent ALMA images of HL Tau show gaps in the dusty disk that may be caused by planetary bodies. Given the young age of this system, if confirmed, this finding would imply very short timescales for planet formation, probably in a…
Measuring the evolution of X-ray emission from pre-main sequence (PMS) stars gives insight into two issues: the response of magnetic dynamo processes to changes in interior structure and the effects of high-energy radiation on…
We investigate the influence of an accretion disk on the angular momentum (AM) evolution of young M dwarfs, which parameters govern the AM distribution after the disk phase, and whether this leads to a mass-independent distribution of SAM.…
The study of the properties of disks around young brown dwarfs can provide important clues on the formation of these very low-mass objects and on the possibility of forming planetary systems around them. The presence of warm dusty disks…
Observations of protoplanetary disks around very low-mass stars and brown dwarfs remain challenging and little is known about their properties. The disk around CIDA1 ($\sim$0.1-0.2$M_\odot$) is one of the very few known disks that host a…
A candidate extrasolar planet companion to the young brown dwarf 2MASSW J1207334-393254 (2M1207) was recently discovered by Chauvin et al. They find that 2M1207 B's temperature and luminosity are consistent with being a young, \~5 M_Jupiter…
We present a study, based on archival XMM-Newton observations, of the extended X-ray emission associated with the inner disk of M33. After the exclusion of point sources with L_X > 2 x 10^{35} erg/s (0.3-6 keV), we investigate the…
Although the environments of star and planet formation are thermodynamically cold, substantial X-ray emission from 10-100 MK plasmas is present. In low mass pre-main sequence stars, X-rays are produced by violent magnetic reconnection…
[Abridged] We map the stellar age distribution ($\lesssim 1$ Gyr) across a 6kpc$\,\times\,$6kpc area of the Galactic disc to constrain our Galaxy's recent star-formation history. Our modelling draws on the sample of Zari et al. (2021) that…