Related papers: Dynamical star-disk interaction in the young stell…

We seek to establish the presence and properties of gas in the circumstellar disk orbiting T Cha, a nearby (d~110 pc), relatively evolved (age ~5-7 Myr) yet actively accreting 1.5 Msun T Tauri star. We used the APEX 12 m radiotelescope to…

We report FUV, optical, and NIR observations of three T Tauri stars in the Orion OB1b subassociation with H$\alpha$ equivalent widths consistent with low or absent accretion and various degrees of excess flux in the mid-infrared. We aim to…

We have modelled the X-ray emission of T Tauri stars assuming that they have isothermal, magnetically-confined coronae. These coronae extend outwards until either the pressure of the hot coronal gas overcomes the magnetic field, or, if the…

Young stars are known to show variability due to non-steady mass accretion rate from their circumstellar disks. Accretion flares can produce strong energetic irradiation and heating that may affect the disk in the planet formation region,…

The properties of accretion disks around stars and brown dwarfs in the SOri cluster (age 3 Myr) are studied based on NIR time series photometry supported by MIR spectral energy distributions. We monitor ~30 young low-mass sources over 8…

We present results from a Near Infrared multi-epoch spectroscopic campaign to detect a young low-mass companion to a T Tauri star. AS 205A is a late-type dwarf (~K5) of ~1 Msun that belongs to a triple system. Independent photometric…

The interplay between T Tauri stars and their circumstellar disks, and how this impacts the onset of planet formation has yet to be established. We studied a seemingly old T Tauri star, PDS 111, and its disk. We analyzed optical, infrared,…

We present an analysis of high-resolution spectroscopy of several bright T Tauri stars using the VLT/CRIRES and Keck/NIRSPEC spectrographs, revealing the first detections of emission from HCN and C2H2 in circumstellar disks at near-infrared…

The high-energy radiation fields of T Tauri stars (TTS) should affect the surrounding circumstellar disk, having implications for disk transport and heating. Yet, observational evidence of the effect of high-energy fields on disks is…

Anomalies in the abundance measurements of short lived radionuclides in meteorites indicate that the protosolar nebulae was irradiated by a high amount of energetic particles (E$\gtrsim$10 MeV). The particle flux of the contemporary Sun…

Accretion onto Classical T Tauri stars is thought to take place through the action of magnetospheric processes, with gas in the inner disk being channeled onto the star's surface by the stellar magnetic field lines. Young stars are known to…

Measurements of masses and ages of young stars from their location in the HR diagram are limited by not only the typical observational uncertainties that apply to field stars, but also by large systematic uncertainties related to…

Observations of the magnetic fields of young solar-type stars provide a way to investigate the signatures of their magnetic activity and dynamos. Spectropolarimetry enables the study of these stellar magnetic fields and was thus employed at…

We present the results of a 2.7 mm continuum interferometric survey of 24 young stellar objects in 11 fields. The target objects range from deeply embedded Class 0 sources to optical T Tauri sources. This is the first sub-arcsecond survey…

In recent years, an increasing number of publications have been addressed to the peculiar and mysterious pre-main sequence star V582 Mon, also known as KH 15D. This extraordinary T Tauri star, located in the young star cluster NGC 2264,…

Theoretical models and spectroscopic observations of newborn stars suggest that protoplantary disks have an inner "wall" at a distance set by the disk interaction with the star. Around T Tauri stars, the size of this disk hole is expected…

We report mid--IR observations of two young stars found in the Taurus dark cloud spatially resolving for the first time their 10 $\mu$m emission. The weak-emission T Tauri star DI Tau, tentatively identified by Skrutskie et al. (1990) on…

We present radiation transfer models of rotating young stellar objects (YSOs) with hotspots in their atmospheres, inner disk warps and other 3-D effects in the nearby circumstellar environment. Our models are based on the geometry expected…

Aims: We want to detect and quantify observables related to accretion processes occurring locally in circumstellar disks, which could be attributed to young forming planets. We focus on objects known to host protoplanet candidates and/or…

We have used the high sensitivity and resolution of the IRAM interferometer to produce sub-arcsecond 12CO 2-1 images of 9 protoplanetary disks surrounding T Tauri stars in the Taurus-Auriga cloud (7 singles and 2 binaries). The images…