Related papers: Silicate Emission in the TW Hydrae Association
Mid-infrared spectra of 65 T Tauri stars (TTS) taken with the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope are modeled using dust at two temperatures to probe the radial variation in dust composition in the uppermost…
The HeII (1640 A) line and the resonance doublet of NV (UV1) provide a good diagnostic tool to constrain the excitation mechanism of hot (Te>40,000K) atmospheric/magnetospheric plasmas in T Tauri stars (TTSs). Making use of the data…
We report the discovery of one RR Lyrae star in the ultra--faint satellite galaxy Hydra II based on time series photometry in the g, r and i bands obtained with the Dark Energy Camera at Cerro Tololo Interamerican Observatory, Chile. The RR…
Given their proximity and age differences, nearby groups of young stars are valuable laboratories for investigations of disk evolution and diversity. The estimated 10-Myr age of groups like the TW Hydrae Association provides a strong…
We exploit the precise parallaxes and proper motions contained in Gaia Data Release 2 (DR2) to establish whether the proposed wide-separation companions to five nearby, young stars are in fact equidistant and comoving with these stars. For…
We discuss the properties of several circumstellar debris disk systems imaged with the Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer in a survey of young stars with known far-IR excesses. These dusty disks…
We present detections of numerous 10-20 micron H2O emission lines from two protoplanetary disks around the T Tauri stars AS 205A and DR Tau, obtained using the InfraRed Spectrograph on the Spitzer Space Telescope. Follow-up 3-5 micron…
The binary T Tauri system JW 566 in the Orion Molecular Cloud underwent an energetic, short-lived flare observed at submillimetre wavelengths by the SCUBA-2 instrument on 26 November 2016 (UT). The emission faded by nearly 50% during the 31…
HR4796 is a young, early A-type star harbouring a well structured debris disk, shaped as a ring with sharp inner edges. It forms with the M-type star HR4796B a binary system, with a proj. sep. ~560 AU. Our aim is to explore the surroundings…
We present mid-infrared photometry of three very young brown dwarfs located in the $\rho$ Ophiuchi star-forming region -- GY5, GY11 and GY310 --obtained with the Subaru 8-meter telescope. All three sources were detected at 8.6 and…
We present the results of a HST/NICMOS coronagraphic survey for the direct detection of substellar companions within the young TW Hydrae and Tucana Associations. At the distance of these associations, the lower mass limit of detection,…
Mid-infrared spectra of planet-forming discs commonly show prominent silicate emission, whose spectral shape is sensitive to the disc temperature distribution as well as its mineralogical composition. We report new James Webb Space…
The unified model of active galactic nuclei (AGN) predicts silicate emission features at 10 and 18 microns in type 1 AGN, and such features have now been observed in objects ranging from distant QSOs to nearby LINERs. More surprising,…
The young stellar object MWC297 is a B1.5Ve star exhibiting strong hydrogen emission lines. This object has been observed by the AMBER/VLTI instrument in 2-telescope mode in a sub-region of the K spectral band centered around the Br gamma…
The goal of the paper is to present new results on light echoes from young stellar objects. Broad band CCD images were obtained over three months at one-to-two week intervals for the field of NGC 6726, using the large field-of-view…
The physical processes occurring within the inner few astronomical units of proto-planetary disks surrounding Herbig Ae stars are crucial to setting the environment in which the outer planet-forming disk evolves and put critical constraints…
This is the first paper in a series of three where we present the first comprehensive inventory of solid state emission bands observed in a sample of 17 oxygen-rich circumstellar dust shells surrounding evolved stars. The data were taken…
As a continuation of our previous studies in 2007 and 2008, new photometric observations of the T Tauri star TW Hya obtained by the MOST satellite and the ASAS project over 40 days in 2009 with temporal resolution of 0.2 days are presented.…
We present photometric detections of dust emission at 850 and 450 micron around the pre-main sequence M1 dwarf TWA 7 using the SCUBA camera on the James Clerk Maxwell Telescope. These data confirm the presence of a cold dust disk around TWA…
We present the X-ray spectrum of TW Hya observed at high and intermediate spectral resolution with the Reflection Grating Spectrometer (RGS) and the European Photon Imaging Camera (EPIC) onboard the XMM-Newton satellite. TW Hya is the first…