Related papers: The outer orbit of the high-mass stellar triple sy…
Context: Massive stars are extremely important for the evolution of the galaxies; there are large gaps in our understanding of their properties and formation, however, mainly because they evolve rapidly, are rare, and distant. It may well…
We present a detailed spectroscopic study of Herschel 36 A (H36A), the main stellar component of the massive multiple system Herschel 36 in the Hourglass Nebula, based on high-resolution optical spectra obtained along an 11 years span. The…
We present the analysis of high-resolution optical spectroscopic observations of the zero-age main-sequence O star Herschel 36 spanning six years. This star is definitely a multiple system, with at least three components detected in its…
Massive stars are of fundamental importance for almost all aspects of astrophysics, but there still exist large gaps in our understanding of their properties and formation because they are rare and therefore distant. It has been found that…
Analyses of multi-epoch, high-resolution (R ~ 50.000) optical spectra of the O-type star HD 152246 (O9 IV according to the most recent classification), complemented by a limited number of earlier published radial velocities, led to the…
Statistics of the angle \Phi between orbital angular momenta in hierarchical triple systems with known inner visual or astrometric orbits are studied. Correlation between apparent revolution directions proves partial orbit alignment known…
We present interferometric observations of the sigma Orionis triple system using the CHARA Array, NPOI, and VLTI. Using these measurements, we spatially resolve the orbit of the close spectroscopic binary (Aa,Ab) for the first time and…
Observations of hierarchical triple star systems show that misalignments are common both between the angular momentum vector of the inner binary and the outer companion orbit, and between the outer binary orbit and a circumtriple gas disk.…
A sample of 278 triple systems with outer separations under 300 au and resolved inner pairs is studied, focusing on the mutual alignment between inner and outer orbits. The degree of alignment increases with (i) decreasing outer separation,…
The recently discovered spectroscopic binary $\rho$ Oph A is a rare magnetic hot binary system composed of two early B-type stars, comprising a non-magnetic primary (Aa) and a slightly less massive magnetic secondary (Ab). Using near-IR…
Kepler-56 is a multi-planet system containing two coplanar inner planets that are in orbits misaligned with respect to the spin axis of the host star, and an outer planet. Various mechanisms have been proposed to explain the broad…
Orbits of inner and outer subsystems in 13 triple or higher-order stellar systems are computed or updated using position measurements and, in three cases, radial velocities. The goal is to determine mutual orbital inclinations, period…
In an effort to determine accurate orbital and physical properties of a large number of bright stars, a method was developed to fit simultaneously stellar parameters (masses, luminosities, effective temperatures), distance, and orbits to…
It is well established that certain detached eclipsing binary stars exhibit apsidal motions whose value is in disagreement with with calculated deviations from Keplerian motion based on tidal effects and the general theory of relativity.…
We describe the circumstances that led to the discovery of Kepler-36b, and the subsequent characterization of its host planetary system. The Kepler-36 system is remarkable for its physical properties: the close separation of the planets,…
We present a study of the orbits of the triple system LHS1070, with the aim to determine individual masses of its components. Sixteen new relative astrometric positions of the three components in the K band were obtained with NACO at the…
Context. HD 150136 is a triple hierarchical system and a non-thermal radio emitter. It is formed by an O3-3.5 V + O5.5-6 V close binary and a more distant O6.5-7 V tertiary. So far, only the inner orbital properties have been reliably…
Analyses of multi-epoch, high-resolution (~ 50000) optical spectra of seven early-type systems provided various important new insights with respect to their multiplicity. First determinations of orbital periods were made for HD 92206C…
Kepler-296 is a binary star system with two M-dwarf components separated by 0.2 arcsec. Five transiting planets have been confirmed to be associated with the Kepler-296 system; given the evidence to date, however, the planets could in…
We present a multi-filter HST/WFPC2 UV-optical study of the Hourglass region in M8. We have extracted the stellar photometry of the sources in the area and obtained the separations and position angles of the Herschel 36 multiple system: for…