Related papers: Resolving the stellar components of the massive mu…

Multiplicity is a ubiquitous characteristic of massive stars. Multiple systems offer us a unique observational constraint on the formation of high-mass systems. Herschel 36 A is a massive triple system composed of a close binary (Ab1-Ab2)…

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…

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…

With the construction of the VLTI (Very Large Telescope Interferometer of the European Observatory ESO for the southern hemisphere) it is now possible to make observations with resolutions of the order of milli-arc-seconds, especially in IR…

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…

delta Velorum is a nearby (24pc) triple stellar system, containing a close, eclipsing binary (Aa, Ab) discovered in 2000. Multiple systems provide an opportunity to determine the set of fundamental parameters (mass, luminosity, size and…

We present high-resolution infrared imaging of the massive star-forming region around the O-star Herschel 36. Special emphasis is given to a compact infrared source at 0".25 southeast of the star. The infrared source, hereafter Her 36 SE,…

The bright southern star Delta Vel is a multiple system comprising at least three stars. Its brightest component, Delta Vel A, was identified in 2000 as one of the brightest eclipsing system in the sky. Its eclipses are easily observable…

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…

We study the Be star $\delta$ Cen circumstellar disk using long-baseline interferometry which is the only observing technique capable of resolving spatially and spectroscopically objects smaller than 5 mas in the H and K b and. We used the…

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,…

As part of our radial velocity planet-search survey performed with SARG at TNG, we monitored the components of HD 132563 for ten years. It is a binary system formed by two rather similar solar type stars with a projected separation of 4.1…

The multiple star system of delta Orionis is one of the closest examples of a system containing a luminous O-type, bright giant star (component Aa1). It is often used as a spectral-type standard and has the highest observed X-ray flux of…

The triple stellar system delta Vel (composed of two A-type and one F-type main sequence stars) is particularly interesting as it contains one of the nearest and brightest eclipsing binaries. It therefore presents a unique opportunity to…

AMBER is the first near infrared focal instrument of the VLTI. It combines three telescopes and produces spectrally resolved interferometric measures. This paper discusses some preliminary results of the first scientific observations of…

Context: For over 12 yr, we have carried out a precise radial velocity survey of a sample of 373 G and K giant stars using the Hamilton \'Echelle Spectrograph at Lick Observatory. There are, among others, a number of multiple planetary…

While the search for exoplanets around main sequence stars more massive than the Sun have found relatively few such objects, surveys performed around giant stars have led to the discovery of more than 30 new exoplanets. The interest in…

We investigate the molecular and dusty environment of OH/IR stars in order to characterize the mass-loss process during the tip-AGB superwind phase. Employing the AMBER instrument at the VLT Interferometer we obtained near-infrared H- and…

The majority of massive stars are located in binary or multiple star systems. Compared to single stars, these objects pose additional challenges to quantitative analyses based on model atmospheres. In particular, little information is…

[Abridged] Aims: This work focuses on one lensed system, HATLAS J142935.3-002836 (H1429-0028), selected in the Herschel-ATLAS field. Gathering a rich, multi-wavelength dataset, we aim to confirm the lensing hypothesis and model the…