Related papers: Relation between spectral indices and binary fract…
The binary fraction among extreme horizontal branch (EHB) stars in Galactic globular clusters (GCs) is an order of magnitude lower than the binary fraction among their counterparts, field hot subdwarfs. This casts serious doubt on their…
Based on a set of over 100 medium- to high-resolution optical spectra collected from 2003 to 2009, we investigate the properties of the O-type star population in NGC6611 in the core of the Eagle Nebula (M16). Using a much more extended data…
Using evolutionary population synthesis we present integrated colours, integrated spectral energy distributions and absorption-line indices defined by the Lick Observatory image dissector scanner (referred to as Lick/IDS) system, for an…
We investigate the binarity properties in field stars using more than 50\,000 main-sequence stars with stellar mass from 0.4 to 0.85\,$M_\odot$ observed by LAMOST and {\emph Gaia} in the solar neighborhood. By adopting a power-law shape of…
We determine the fraction of G-dwarf stars that could host stable planetary systems based on the observed properties of binaries in the Galactic field, and in various postulated primordial binary populations, which assume that the…
We analyze the wavelength dependence of the far-infrared polarization fraction toward the OMC-1 star forming region using observations from HAWC+/SOFIA at 53, 89, 154, and 214 $\mu$m. We find that the shape of the far-infrared polarization…
If not properly accounted for, unresolved binary stars can induce a bias in the photometric determination of star cluster masses inferred from star counts and the luminosity function. A correction factor close to 1.15 (for a binary fraction…
Aims. Having established the binary status of nineteen O-type stars located in four Cygnus OB associations, we now determine their fundamental parameters to constrain their properties and their evolutionary status. We also investigate their…
Binaries are very common in galaxies, and more than half of Galactic hot subdwarf stars, which are thought as a possible origin of UV-upturn of old stellar populations, are found in binaries. Previous works showed that binary evolution can…
In dense environments like globular clusters (GCs), dynamical interactions can disrupt or harden close binaries, nonetheless, detailed comparisons with field binary fractions remain limited. Here, we present an analysis of the close binary…
The formation of stars above about twenty solar masses and their apparently high multiplicity remain heavily debated subjects in astrophysics. We have performed a vast high-resolution radial velocity spectroscopic survey of about 250 O- and…
Wide binaries, with separations between two stars from a few AU to more than several thousand AU, are valuable objects for various research topics in Galactic astronomy. As the number of newly reported wide binaries continues to increase,…
(Abbreviated) We have used precise radial velocity measurements of subdwarf-B stars from the Palomar-Green catalogue to look for binary extreme horizontal branch (EHB) stars. We identify 36 EHB stars in our sample and find that at least 21…
We used deep observations collected with ACS@HST to derive the fraction of binary systems in a sample of thirteen low-density Galactic globular clusters. By analysing the color distribution of Main Sequence stars we derived the minimum…
The advent of new and more powerful infrared spectrographs has significantly motivated the advancement of the study of atomic and molecular line lists and stellar atmosphere models. While optical abundance determinations rely on extensively…
We present the results of a survey of N-body simulations aimed at exploring the evolution of compact binaries in multiple-population globular clusters.We show that as a consequence of the initial differences in the structural properties of…
We present the results of a long-term high-resolution spectroscopy campaign on the O-type stars in NGC 6231. We revise the spectral classification and multiplicity of these objects and we constrain the fundamental properties of the O-star…
The recently-discovered lack of close binaries, among extreme horizontal branch (EHB) stars in Galactic globular clusters, has thus far constituted a major puzzle, in view of the fact that blue subdwarf stars - the field counterparts of…
Binary stars are common in star clusters and galaxies, but the detailed effects of binary evolution are not taken into account in some colour-magnitude diagram (CMD) studies. This paper studies the CMDs of twelve globular clusters via…
Current stellar population models have arguably the largest uncertainties in the near-IR wavelength range, partly due to a lack of large and well calibrated empirical spectral libraries. In this paper we present a project, which aim it is…