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Evidence for a co-moving sub-stellar companion of GQ Lup
We present a companion of the ≤2 Myr young classical T Tauri star GQ Lup in the Lupus star forming region at 140 ± 50 pc from imaging, astrometry, and spectroscopy. With direct K-band imaging usingExpand
X-ray emission from young stars in Taurus-Auriga-Perseus: Luminosity functions and the rotation - activity - age - relation
We report on a systematic search for X-ray emission from pre-main sequence and young main sequence stars in the Taurus-Auriga-Perseus region. Our stellar sample consists of all T Tauri stars from theExpand
Masses and luminosities of O- and B-type stars and red supergiants
Massive stars are of interest as progenitors of supernovae, i.e. neutron stars and black holes, which can be sources of gravitational waves. Recent population synthesis models can predict neutronExpand
Toward a mass and radius determination of the nearby isolated neutron star RX J185635-3754
We discuss efforts to determine the mass, radius, and surface composition of the nearby compact object RX J185635-3754 from its multiwavelength spectral energy distribution. We compute nonmagnetizedExpand
Search for young stars among ROSAT All-Sky Survey X-ray sources in and around the R CrA dark cloud ⋆
We present the ROSAT All-Sky Survey data in a 126 deg 2 area in and around the CrA star forming region. With low-resolution spectroscopy of unidentied ROSAT sources we could nd 19 new pre-mainExpand
Gl 86B: a white dwarf orbits an exoplanet host star
In this Letter we present our first high-contrast observations of the exoplanet host star Gl 86 using NAOS-CONICA (NACO) and its new Simultaneous Differential Imager (SDI) as well as results fromExpand
Identifying birth places of young isolated neutron stars
Young isolated radio-quiet neutron stars are still hot enough to be detectable at X-ray and optical wavelengths due to their thermal emission and can hence probe cooling curves. An identification ofExpand
Direct detection of exoplanet host star companion γ Cep B and revised masses for both stars and the sub-stellar object
Context. The star γ Cep is known as a single-lined spectroscopic triple system at a distance of 13.8 pc, composed of a K1 III-IV primary star with V = 3.2 mag, a stellar-mass companion in a 66-67Expand
The origin of RX J1856.5−3754 and RX J0720.4−3125 – updated using new parallax measurements
RX J1856.5−3754 and RX J0720.4−3125 are the only young isolated radio-quiet neutron stars (NSs) for which trigonometric parallaxes were measured. Due to detection of their thermal emission in X-rays,Expand
Radial Velocity Survey of Members and Candidate Members of the TW Hydrae Association
We report spectroscopic observations of stars belonging to the young nearby group known as the TW Hydrae association, as well as of a number of potential members of the association identified inExpand