Related papers: S Coronae Australis -- a T Tauri Twin

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…

The rich absorption spectra of Sun-like stars are enticing probes for variations in the fine-structure constant, $\alpha$, which gauges the strength of electromagnetism. While individual line wavelengths are sensitive to $\alpha$, they are…

Results of the time variability monitoring of the two classical T Tauri stars, RU Lup and IM Lup, are presented. Three photometric data sets were utilised: (1) simultaneous (same field) MOST satellite observations over four weeks in each of…

We present an H-band image of FS Tauri, a 0.2"-separated classical T Tauri binary system, taken with the Coronagraphic Imager with Adaptive Optics on the Subaru Telescope. This new image, combined with Hubble Space Telescope / Advanced…

We present rotation periods for the solar-type primary stars in 13 close (a~< 5 AU) single-lined spectroscopic binaries with known orbital periods (P) and eccentricities (e). All binaries are members of the open clusters M35 (150Myr) and…

Using the Infrared Spectrograph aboard the Spitzer Space Telescope, we observed multiple epochs of 11 actively accreting T Tauri stars in the nearby Taurus-Auriga star forming region. In total, 88 low-resolution mid-infrared spectra were…

Binary star-formation theory predicts that close binaries (a<100 AU) will experience periodic pulsed accretion events as streams of material form at the inner edge of a circumbinary disk, cross a dynamically cleared gap, and feed…

We report JVLA 8-10 GHz ($\lambda$=3.0-3.7 cm) monitoring observations toward the YSO cluster R Coronae Australis (R\,CrA), taken in 2012, from March 15 to September 12. These observations were planned to measure the radio flux…

The ASCA satellite has recently detected variable hard X-ray emission from two Class I protostars in the rho Oph cloud, YLW15 (IRS43) and WL6, with a characteristic time scale ~20h. In YLW15, the X-ray emission is in the form of…

The Chandra X-ray observatory monitored the single cool star, AB Doradus, continuously for a period lasting 88ksec (1.98 Prot) in 2002 December with the LETG/HRC-S. The X-ray lightcurve shows significant rotational modulation. It can be…

We present here the results of our observations of TrES-2 using the Infrared Array Camera on Spitzer. We monitored this transiting system during two secondary eclipses, when the planetary emission is blocked by the star. The resulting…

Luminous X-ray stars are very often found in visual double or multiple stars. Binaries with periods of a few days possess the highest degree of coronal X-ray activity among regular, non-relativistic stars because of their fast, tidally…

The small separation of the individual stellar components in the TTau system has prevented spectroscopy of the individual components in the near-infrared (NIR) in the past. We present NIR data (H- and K-band) on this object taken using the…

We present theoretical models for the evolution of T Tauri stars surrounded by circumstellar discs. The models include the effects of pre-main-sequence stellar and time dependent disc evolution, and incorporate the effects of stellar…

Delta Scuti ($\delta$ Sct) stars are intermediate-mass pulsators, whose intrinsic oscillations have been studied for decades. However, modelling their pulsations remains a real theoretical challenge, thereby even hampering the precise…

We investigate the binary star T Tauri South, presenting the orbital parameters of the two components and their individual masses. We combined astrometric positions from the literature with previously unpublished VLT observations. Model…

We present a spectrophotometric analysis of S Ori J053825.4-024241, a candidate member close to the substellar boundary of the young (1-8 Myr), nearby (~360 pc) sigma Orionis star cluster. Our optical and near-infrared photometry and…

We report here the first results of a multi-wavelength campaign focussing on magnetospheric accretion processes within the close binary system V4046 Sgr, hosting two partly-convective classical T Tauri stars of masses ~0.9 Msun and age ~12…

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…

We have produced brightness and magnetic field maps of the surfaces of CV Cha and CR Cha: two actively accreting G and K-type T Tauri stars in the Chamaeleon I star-forming cloud with ages of 3-5 Myr. Our magnetic field maps show evidence…