Related papers: T Tauri Multiple Systems
The mass-accretion rate, Macc, is a crucial parameter for the study of the evolution of accretion disks around young low-mass stellar objects (YSOs) and for planet formation studies. The Taurus star forming region (SFR) is rich in pre-main…
We summarize here the observed properties of ``infrared companions'' to T Tauri stars and argue that their observational properties are identical to those of Class I sources. They may therefore be embedded protostars in a much earlier…
ISO observations will improve our understanding of disks around low-mass pre-main-sequence stars in various ways. In particular, ISO can measure simultaneously spectral energy distributions and low-resolution spectra from 2 to 12 \um of T…
I review the observational challenges of finding post T Tauri stars (PTTS), defined here as low-mass, pre-main-sequence stars with ages of 10^7-10^8 yr. Such stars are difficult to find because they are less active than younger T Tauri…
Accreting T Tauri stars are observed to be less luminous in X-rays than non-accretors, an effect that has been detected in various star forming regions. To explain this we have combined, for the first time, a radiative transfer code with an…
The observable characteristics and subsequent evolution of young stellar populations is dominated by their massive stars. As our understanding of those massive stars and the factors affecting their evolution improves, so our interpretation…
Direct imaging in the infrared at the diffraction limit of large telescopes is a unique probe of the properties of young planetary systems. We survey 55 single class I and class II stars in Taurus in the L' filter using natural and laser…
We present the properties of a group of young stars associated with the well-studied T Tauri star system AS 353, located in the Aquila star-forming region. The association is identified using radial velocity measurements of sample objects…
Despite the revolution in our knowledge resulting from the detection of planets around mature stars, we know almost nothing about planets orbiting young stars because rapid rotation and active photospheres preclude detection by radial…
For three decades, adaptive optic surveys have revealed an excess of T Tauri binaries across a = 10-100 au in nearby star-forming regions compared to the field population of main-sequence (MS) stars. Such an excess requires that most stars…
The optical star in the T Tauri triple system is the prototype of young sun-like stars in our galaxy. This complex and dynamic system has evidence for misaligned disks and outflows, and molecular material in a circumbinary ring that…
We employ a Monte Carlo radiation transfer code to investigate the multi- wavelength photopolarimetric variability arising from a spotted T Tauri star surrounded by a dusty circumstellar disk. Our aim is to assess the ability of the…
The closest examples of high-mass star birth occurs in deeply embedded environments at kiloparsec distances. Although much progress has been made, an observationally validated picture of the dominant processes which allows the central…
Recent adaptive optics systems in astronomy achieve high-angular resolution. With the extreme stability of the images, detection at very low fluxes can be reached using a coronograph at the diffraction limit of the telescopes. This paper is…
The recent discovery of a transiting planet around WASP-33, the misalignment of the stellar rotation axis and the planet orbit, the possible existence of an additional planet in the system, and the presence of $\delta$ Scuti pulsations in…
Large area surveys will dominate the next decade of astronomy, and the main limitation to science will be the thorough followup and characterization of their extremely numerous discoveries. The deployment of robotic laser adaptive optics on…
Recent observations of nearby star forming regions have offered evidence that young brown dwarfs undergo a period of mass accretion analogous to the T Tauri phase observed in young stars. Brown dwarf analogs to stellar protostars, however,…
We present a high spatial resolution, 10-20 micron survey of 65 T Tauri binary stars in Taurus, Ophiuchus, and Corona Australis using the Keck 10 m telescopes. Designed to probe the inner ~1 AU region of the circumstellar disks around the…
(abridged) The old Star Cluster (SC) systems surrounding any sofar investigated galaxy represent a powerful tool for the understanding of the cosmological evolution of their host galaxies. Phases of enhanced cluster formation can be…
Using speckle-interferometry we have carried out repeated measurements of relative positions for the components of 34 T Tauri binary systems. The projected separation of these components is low enough that orbital motion is expected to be…