Related papers: Accretion, jets and winds: High-energy emission fr…
The proliferation of high time-resolution and decades-long monitoring of classical T Tauri stars provides a vast opportunity to test the variability of the star-disk connections. However, most monitoring surveys use single broad-band…
Context: A large sample of T Tauri stars exhibits optical jets, approximately half of which rotate slowly, only at ten per cent of their breakup velocity. The disk-locking mechanism has been shown to be inefficient to explain this…
We have carried out a near-infrared imaging survey of luminous young stellar outflow candidates using the United Kingdom Infrared Telescope. Observations were obtained in the broad band K (2.2 mu) and through narrow band filters at the…
The near-star environment around young stars is very dynamic with winds, disks, and outflows. These processes are involved in star and planet formation, and influence the formation and habitability of planets around host stars. Even for the…
We present the first high-resolution X-ray spectrum of a prototypical Herbig star (AB Aurigae), measure and interpret various spectral features, and compare our results with model predictions. We use X-ray spectroscopy data from XMM-Newton.…
T Tauri stars are young, low mass, pre-main sequence stars surrounded by an accretion disk. These objects present strong magnetic activity and powerful magnetic reconnection events. Strong shocks are likely associated with fast reconnection…
Early Herbig Be (HBe) stars are massive, young stars accreting through the Boundary Layer mechanism. However, given the rapid ($<$ 2 Myr) evolution of early Herbig stars to the main-sequence phase, studying the evolution of the…
Magnetospheric accretion is a key process that shapes the inner disks of T Tauri stars, controlling mass and angular momentum evolution. It produces strong ultraviolet and optical emission that irradiates the planet-forming environment. In…
The stellar magnetic field completely dominates the environment around late-type stars. It is responsible for driving the coronal high-energy radiation (e.g. EUV/X-rays), the development of stellar winds, and the generation transient events…
The nature of the magnetic coupling between T Tauri stars and their disks determines not only the mass accretion process but possibly the spin evolution of the central star. We have taken a recently-published surface magnetogram of one…
This work presents CHARA/VEGA H$\alpha$ spectro-interferometry (R ~ 6000, and $\lambda$/2B ~ 1 mas) of HD 179218 and HD 141569, doubling the sample of Herbig Ae/Be (HAeBe) stars for which this type of observations is available so far. The…
FU Orionis stars (FUors) are young low-mass eruptive stars that are thought to be accreting at high rates. They could give rise to soft X-ray emission from accretion shocks, but their X-ray properties are largely unknown. We report the…
Protostellar jets are tightly connected to the accretion process and regulate the angular momentum balance of accreting star-disk systems. The DG Tau jet is one of the best-studied protostellar jets and contains plasma with temperatures…
Models of magnetically driven accretion and outflows reproduce many observational properties of T Tauri stars. For the more massive Herbig Ae/Be stars, the corresponding picture is not well established. Nonetheless, it is expected that…
Observations of galactic BHCs made by the Compton GRO in the hard X-ray and gamma-ray bands have significantly enhanced our knowledge of the emission properties of these objects. Understanding these observations presents a formidable…
The discovery of optical jets immersed in the strong UV radiation field of the Rosette Nebula sheds new light on, but meanwhile poses challenges to, the study of externally irradiated jets. The jet systems in the Rosette are found to have a…
We present high resolution X-ray spectra of the X-ray bright classical T Tauri star, TW Hydrae, covering the wavelength range of 1.5-25 AA. The differential emission measure derived from fluxes of temperature-sensitive emission lines shows…
Most of the observed emission lines and continuum excess from young accreting low mass stars (Classical T Tauri stars -- CTTSs) take place in the star-disk or inner disk region. These regions have a complex emission topology still largely…
Protons can be plausibly accelerated to $\sim 10^{18}$-$10^{19}$ eV in strong accretion shocks surrounding massive clusters of galaxies. Such protons efficiently produce very high energy pairs through interactions with the CMB, which then…
Interpreting the short-timescale variability of the accreting, young, low-mass stars known as Classical T Tauri stars remains an open task. Month-long, continuous light curves from the Transiting Exoplanet Survey Satellite (\textit{TESS})…