Related papers: Measuring Accretion in Young Substellar Objects: A…
We have measured the present accretion rate of roughly 800 low-mass (~1-1.4 Mo) pre-Main Sequence stars in the field of Supernova 1987A in the Large Magellanic Cloud (LMC, Z~0.3 Zo). It is the first time that this fundamental parameter for…
We present high-quality, medium resolution X-shooter/VLT spectra in the range 300-2500 nm for a sample of 12 very low-mass stars in the \sigma Orionis cluster. The sample includes stars with masses ranging from 0.08 to 0.3 M$_\odot$. The…
As part of a multi-faceted program to investigate the origin and early evolution of sub-stellar objects, we present high-resolution Keck optical spectra of 14 very low mass sources in the IC 348 young cluster and the Taurus star-forming…
Stars collect most of their mass during the protostellar stage, yet the accretion luminosity and stellar parameters, which are needed to compute the mass accretion rate, are poorly constrained for the youngest sources. The aim of this work…
Accretion among planets is a poorly understood phenomenon, due to lack of both observational and theoretical studies. Detection of emission lines from accreting gas giants facilitate detailed investigations into this process. This work…
Accretion plays a central role in the physics that governs the evolution and dispersal of protoplanetary disks. The primary goal of this paper is to analyze the stability over time of the mass accretion rate onto TW Hya, the nearest…
We present high-resolution optical spectra of 15 objects near or below the sub-stellar limit in the Upper Scorpius and $\rho$ Ophiuchus star-forming regions. These spectra, obtained with the HIRES instrument on the Keck I telescope, are…
Much is known about the processes driving accretion from protoplanetary disks onto low-mass pre-main-sequence stars (T Tauri stars). Nevertheless, it is unclear how accretion stops. To determine the accretion properties and their relation…
We present X-Shooter/VLT observations of a sample of 36 accreting low-mass stellar and sub-stellar objects (YSOs) in the Lupus star forming region, spanning a range in mass from ~0.03 to ~1.2Msun, but mostly with 0.1Msun < Mstar < 0.5Msun.…
We report the first comprehensive study of emission line variability in an accreting young brown dwarf. We have collected 14 high-resolution optical spectra of 2MASSW J1207334-393254 (M8), a likely member of the nearby 8-million-year-old TW…
Briceno et al. recently used optical imaging, data from the Two-Micron All-Sky Survey (2MASS), and follow-up spectroscopy to search for young low-mass stars and brown dwarfs in 8 square degrees of the Taurus star-forming region. By the end…
We have measured the surface magnetic flux on four accreting young brown dwarfs and one non-accreting young very low-mass star utilizing high resolution spectra of absorption lines of the FeH molecule. A magnetic field of 1-2 kG had been…
We have performed a search for planetary-mass brown dwarfs in the Chamaeleon I star-forming region using proper motions and photometry measured from optical and infrared images from the Spitzer Space Telescope, the Hubble Space Telescope,…
We present HST-COS FUV and -STIS optical observations towards the young accreting brown dwarf 2MASS-J08440915-7833457 (J0844) from the ULLYSES DDT Program. We analyse hot FUV lines such C IV, Si IV, and N V, as well as fluorescent emission…
We present new VLT/X-Shooter optical and NIR spectra of a sample of 17 candidate young low-mass stars and BDs in the rho-Ophiucus cluster. We derived SpT and Av for all the targets, and then we determined their physical parameters. All the…
By collecting optical and infrared photometry and low resolution spectroscopy, we have identified a large number of low mass stars and brown dwarf candidates belonging to the young cluster (~5 Myr) associated with the binary star lambda…
A planetary growth rate, a.k.a., the mass accretion rate, is a fundamental parameter in planet formation, as it determines a planet's final mass. Planetary mass accretion rates have been estimated using hydrogen lines, based on the models…
Recent observations show a strong correlation between stellar mass and accretion rate in young stellar and sub-stellar objects, with the scaling $\dot{M}_{acc} \propto M_*^2$ holding over more than four orders of magnitude in accretion…
The pre-main-sequence evolution of low-mass stars and brown dwarfs is studied numerically starting from the formation of a protostellar/proto-brown dwarf seed and taking into account the mass accretion onto the central object during the…
While the rate of accretion onto T Tauri stars is predicted to decline with age, objects with strong accretion have been detected up to ages of 10 Myr. We analyze a sample of these old accretors identified by having a significant $U$ band…