Related papers: Dynamical Masses for Low-Mass Pre-Main Sequence St…
We report spectroscopic and interferometric observations of the moderately metal-poor double-lined binary system HD 195987, with an orbital period of 57.3 days. By combining our radial-velocity and visibility measurements we determine the…
We present subarcsecond angular resolution observations carried out with the Submillimeter Array (SMA) at 880 $\mu$m centered at the B0-type protostar GGD27~MM1, the driving source of the parsec scale HH 80-81 jet. We constrain its…
High-mass multiples might form via fragmentation of self-gravitational disks or alternative scenarios such as disk-assisted capture. However, only few observational constraints exist on the architecture and disk structure of high-mass…
$\mu$ Her is a nearby quadruple system with a G-subgiant primary and several low mass companions arranged in a 2+2 architecture. While the BC components have been well characterized, the Ab component has been detected astrometrically and…
Based on measurements with the Effelsberg 100-m telescope, a multi-line study of molecular species is presented toward the gravitational lens system PKS1830-211. Obtaining average radial velocities and performing Large Velocity Gradient…
We present the first orbital elements for the massive close binary, HD 115071, a double-lined spectroscopic binary in a circular orbit with a period of 2.73135 +/- 0.00003 days. The orbital semiamplitudes indicate a mass ratio of M_2/M_1 =…
We report the discovery of a double-lined, spectroscopic, eclipsing binary in the Orion star-forming region. We analyze the system spectroscopically and photometrically to empirically determine precise, distance-independent masses, radii,…
HD 213597 is an eclipsing binary system which was detected by the STEREO spacecraft and was speculated to host a low-mass stellar companion. We used high-resolution spectroscopy with the 10-m Hobby-Eberly Telescope and the 1.2-m telescope…
The triple-lined spectroscopic triple system HD 109648 has one of the shortest periods known for the outer orbit in a late-type triple, 120.5 days, and the ratio between the periods of the outer and inner orbits is small, 22:1. With such…
With Hubble Space Telescope Fine Guidance Sensor astrometry and previously published radial velocity measures we explore the exoplanetary system HD 202206. Our modeling results in a parallax, $\pi_{abs} = 21.96\pm0.12$ milliseconds of arc,…
The predicted orbital-period distribution of the subdwarf-B (sdB) population is bi-modal with a peak at short (< 10 days) and long (> 500 days) periods. Observationally, many short-period sdB systems are known, but only few wide sdB…
We consider a model for the cyclic brightness variations of a young star with a low-mass companion that accretes matter from the remnants of a protostellar cloud. At small inclinations of the binary orbit to the line of sight, the streams…
Stellar evolution models of B-type stars are still uncertain in terms of internal mixing properties, notably in the area between the convective core and the radiative envelope. This impacts age determination of such stars in addition to the…
We report individual dynamical masses of $66.92 \pm 0.36 \; M_{Jup}$ and $53.25 \pm 0.29 \; M_{Jup}$ for the binary brown dwarfs $\varepsilon$ Indi Ba and Bb, measured from long term ($\approx 10$ yr) relative orbit monitoring and absolute…
mu Orionis was identified by spectroscopic studies as a quadruple star system. Seventeen high precision differential astrometry measurements of mu Ori have been collected by the Palomar High-precision Astrometric Search for Exoplanet…
[abridged] We have assembled a database of stars having both masses determined from measured orbital dynamics and sufficient spectral and photometric information for their placement on a theoretical HR diagram. Our sample consists of 115…
We report the discovery of a pre-main-sequence, low-mass, double-lined, spectroscopic, eclipsing binary in the Orion star-forming region. We present our observations including radial velocities derived from optical high-resolution…
We present the ASCA results of intermediate-mass pre-main-sequence stars (PMSs), or Herbig Ae/Be stars (HAeBes). Among the 35 ASCA pointed-sources, we detect 11 plausible X-ray counterparts. X-ray luminosities of the detected sources in the…
We present spectroscopic observations of the massive multiple system HD\,167971, located in the open cluster NGC\,6604. The brighter component of the triple system is the overcontact eclipsing binary MY\,Ser with an orbital period of…
We present polarimetric observations of a massive pre-main sequence short-period binary star of the Herbig Ae/Be type, MWC 1080. The mean polarization at 7660 A is 1.60% at 81.6 deg, or 0.6% at 139 deg if an estimate of the interstellar…