Related papers: Face to phase with RU Lupi
(Abridged) High dispersion spectrographs on large aperture telescopes have recently allowed observers to study the stellar and accretion properties of deeply embedded young stars, commonly referred to as Class I stars. We summarize these…
It is shown that the existence of a hot accretion spot on the surface of classical T Tauri stars allows to explain observed veiling of their photospheric spectrum not only in the visible but also in the near infrared spectral band.
We perform three-dimensional magnetohydrodynamic simulations of magnetospheric accretion in a T Tauri star to study the accretion and wind structures in the close vicinity of the star. The gas accreting onto the star consists of the gas…
We present high resolution (R ~ 60,000) circular spectropolarimetry of the classical T Tauri star TW Hydrae. We analyze 12 photospheric absorption lines and measure the net longitudinal magnetic field for 6 consecutive nights. While no net…
We present orbit-resolved spectroscopic and photometric observations of the polar ST LMi during its recent low and high states. In the low state spectra, we report the presence of blue and red satellites to the H-alpha emission line; the…
Classical T Tauri stars are pre-main-sequence objects that undergo simultaneous accretion, wind outflow, and coronal X-ray emission. The impact of plasma on the stellar surface from magnetospheric accretion streams is likely to be a…
Spectral observations of classical T Tauri stars show a wide range of line profiles, many of which reveal signs of matter inflow and outflow. Halpha is the most commonly observed line profile due to its intensity, and it is highly dependent…
We have analyzed high spatial, moderate spectral resolution observations of Eta Carinae obtained with the STIS from 1998.0 to 2004.3. The spectra show prominent P-Cygni lines in H I, Fe II and He I which are complicated by blends and…
The YY Ori stars are T Tauri stars with prominent time-variable redshifted absorption components that flank certain emission lines. One of the brightest in this class is S CrA, a visual double star. We have obtained a series of…
Medium-resolution $(R\simeq 15000)$ circular spectropolarimetry of T Tauri is presented. The star was observed twice: on November 11, 1996 and January 22, 2002. Weak circular polarization has been found in photospheric absorption lines,…
We present new red optical spectra of V592 Cas aimed at exploring the properties of the outflow of this system in a spectral region where the underlying white dwarf and the accretion disk do not contribute significantly to the observed…
The circumstellar environments of classical T Tauri stars are challenging to directly image because of their high star-to-disk contrast ratio. One method to overcome this is by using imaging polarimetry where scattered and consequently…
Winds in protoplanetary disks play an important role in their evolution and dispersal. However, what physical process is driving the winds is still unclear (i.e. magnetically vs thermally driven), and can only be understood by directly…
We discuss key observational signatures of Classical T Tauri stars (CTTSs) accreting through Rayleigh-Taylor instability, which occurs at the interface between an accretion disk and a stellar magnetosphere. In this study, the results of…
We characterize the physical properties of T Chamaeleontis, a transitional T Tauri star showing UX Ori-type variability, and of its associated disc, and probe possible effects of disc clearing processes. Different spectral diagnostics are…
RZ Psc is an isolated high-latitude post-T Tauri star that demonstrates a UX Ori-type photometric activity. The star shows very weak spectroscopic signatures of accretion, but at the same time possesses the unusual footprints of the wind in…
We present measurements of the longitudinal magnetic field in the circumstellar environment of seven classical T Tauri stars. The measurements are based on high-resolution circular spectropolarimetry of the He I 5876 emission line, which is…
The classical T Tauri star RW Aur A is an irregular variable with a large amplitude in all photometric bands. In an extended series of photometric data we found small-amplitude periodic variations in the blue colours of the star, with a…
We used the WINERED spectrograph to perform near-infrared high-resolution spectroscopy (resolving power $R = 28$,000) of 13 young intermediate-mass stars in the Taurus star-forming region. Based on the presence of near- and mid-infrared…
[Ne II] 12.81 $\mu\mathrm{m}$ emission is a well-used tracer of protoplanetary disk winds due to its blueshifted line profile. MIRI-MRS recently observed T Cha, detecting this line along with lines of [Ne III], [Ar II] and [Ar III], with…