Related papers: GG Tau A: Dark shadows on the ringworld

CI Tau is currently the only T Tauri star with an inner protoplanetary disk that hosts a planet, CI Tau b, that has been detected by a radial velocity survey. This provides the unique opportunity to study disk features that were imprinted…

IRAS~04158+2805 has long been thought to be a very low mass T-Tauri star (VLMS) surrounded by a nearly edge-on, extremely large disc. Recent observations revealed that this source hosts a binary surrounded by an extended circumbinary disc…

We present extended Spectral Energy Distributions (SEDs) of seven classical RV Tauri stars, using newly obtained submillimetre continuum measurements and Geneva optical photometry supplemented with literature data. The broad-band SEDs show…

We report high-resolution (0.07 arcsec) near-infrared polarized intensity images of the circumstellar disk around the star 2MASS J16042165-2130284 obtained with HiCIAO mounted on the Subaru 8.2 m telescope. We present our $H$-band data,…

We use spectrally dispersed near-IR interferometry data to constrain the temperature profiles of sub-AU-sized regions of 11 Herbig Ae/Be sources. We find that a single-temperature ring does not reproduce the data well. Rather, models…

We present the results of adaptive optics nulling interferometric observations of two Herbig Ae stars, AB Aur and V892 Tau. Our observations at 10.3 microns show resolved circumstellar emission from both sources. Further analysis of the AB…

DR Tau has been noted for its unusually high variability in comparison with other T Tauri stars. Although it is one of the most extensively studied pre-main sequence stars, observations with millimeter interferometry have so far been…

We present high quality near infrared imaging polarimetry of HL Tau at 0.4 to 0.6 arcsec resolution, obtained with Subaru/CIAO and UKIRT/IRCAM. 3-D Monte Carlo modelling with aligned oblate grains is used to probe the structure of the…

We analyze HST/GHRS spectra of AB Doradus, the prototypical ultra-rapidly rotating K dwarf. We observed chromospheric (Mg II) and transition region (C II, Si IV, C IV, and N V) lines periodically throughout the stellar rotation period, and…

Aims: We aim at spatially and spectrally resolving the innermost scale of the young stellar object CI Tau to constrain the inner disk properties and better understand the magnetospheric accretion phenomenon. Methods: The high sensitivity…

Young stars are frequently observed to host circumstellar disks, within which their attendant planetary systems are formed. Scattered light imaging of these proto-planetary disks reveals a rich variety of structures including spirals, gaps…

We present new observations of CO J=2-1 emission from the protoplanetary disk around TW Hya. Emission is detected out to 240 au (4") and found to exhibit azimuthal variations up to 20% beyond 180 au (3"), with the west side of the disk…

In this contribution we investigate how a disk determines the physical and geometrical properties of the circumstellar environment of the T Tauri SU Aurigae. Our model of the spectral energy distribution of this star includes the central…

AU Microscopii is a 12 Myr old M dwarf that harbors an optically thin, edge-on disk of dust. The scattered light surface brightness falls with projected distance b from the star as b^-a; within b = 43 AU, a = 1-2, while outside 43 AU, a =…

High-energy irradiation of the circumstellar material might impact the structure and the composition of a protoplanetary disk and hence the process of planet formation. In this paper, we present a study on the possible influence of the…

We present a sensitive, multiwavelength submillimeter continuum survey of 153 young stellar objects in the Taurus-Auriga star formation region. The submillimeter detection rate is 61% to a completeness limit of ~10 mJy (3-sigma) at 850…

Context. The study of protoplanetary disks is fundamental to understand their evolution and interaction with the surrounding environment, and to constrain planet formation mechanisms. Aims. We aim at characterising the young binary system…

In this contribution we give a progress report on our systematic study of a large sample of post-AGB stars. The sample stars were selected on the basis of their infrared colours and the selection criteria were tuned to discover objects with…

We present 7-mm continuum observations of 14 low-mass pre-main-sequence stars in the Taurus-Auriga star-forming region obtained with the Very Large Array with ~1.5" resolution and ~0.3 mJy rms sensitivity. For 10 objects, the circumstellar…

The formation scenario of a gapped disk, i.e., transitional disk, and its asymmetry is still under debate. Proposed scenarios such as disk-planet interaction, photoevaporation, grain growth, anticyclonic vortex, eccentricity, and their…