Related papers: On Binary Channels to Anomalous Cepheids
(abridged) We present the results of a variable star search in Andromeda II, a dwarf spheroidal galaxy companion to M31, using HST/WFPC2 observations. Seventy-three variables were found, one of which is an anomalous Cepheid while the others…
It is now clear that a binary formation pathway is responsible for a significant fraction of planetary nebulae, and this increased sample of known binaries means that we are now in a position to begin to constrain their influence on the…
Many problems in contemporary astrophysics---from understanding the formation of black holes to untangling the chemical evolution of galaxies---rely on knowledge about binary stars. This, in turn, depends on discovery and characterization…
Binaries are excellent astrophysical laboratories that provide us with direct measurements of fundamental stellar parameters. Compared to single isolated star, multiplicity induces new processes, offering the opportunity to confront our…
The stability criteria of rapid mass transfer and common-envelope evolution are fundamental in binary star evolution. They determine the mass, mass ratio, and orbital distribution of many important systems, such as X-ray binaries, type Ia…
Stellar systems composed of single, double, triple or high-order systems are rightfully regarded as the fundamental building blocks of the Milky Way. Binary stars play an important role in formation and evolution of the Galaxy. Through…
Massive stars play a major role in the evolution of their host galaxies, and serve as important probes of the distant Universe. It has been established that the majority of massive stars reside in close binaries and will interact with their…
Binary stars and their interactions shape the formation of compact binaries, supernovae, and gravitational wave sources. The efficiency of mass transfer - the fraction of mass retained by the accretor during binary interaction - is a…
For synthesising star clusters and whole galaxies, stellar populations need to be modelled by a set of four functions that define their initial distribution of stellar masses and of the orbital properties of their binary-star populations.…
The recent discovery and analysis of a classical Cepheid in the well detached, double-lined, eclipsing binary OGLE-LMC-CEP0227, has provided the first determination of the dynamical mass of a classical Cepheid variable to an unprecedented…
The existence of strange quark stars has been proposed many years ago. More recently, the possible co-existence of a first family composed of "normal" neutron stars with a second family of strange quark stars has been proposed as a solution…
The rapid rotation of Be stars is supposed to mainly originate from binary evolution. In recent years, more and more Be stars with helium (He) star companions have been discovered, which provides a significant opportunity to study binary…
Abundance anomalies observed in globular cluster stars indicate pollution with material processed by hydrogen burning. Two main sources have been suggested: asymptotic giant branch stars and massive stars rotating near the break-up limit.…
A significant fraction of massive stars are found in multiple systems. The effect of binarity on stellar evolution is poorly constrained. In particular, the role of tides and mass transfer on surface chemical abundances is not constrained…
Which sample of objects can give strong constraints on single-star evolution theory ? Whilst star cluster members share the same age and the same metallicity, many questions (e.g. field stars contamination, stellar rotation, presence of…
The popularity of pulsating stars resides in their capacity of determining several crucial and relevant parameters such as heliocentric distances, ages, metallicity gradients and reddening. RR Lyrae stars are old stellar tracers and have…
(abridged) Type II and anomalous Cepheids (ACs) are useful distance indicators when there are too few classical Cepheids or when RR Lyrae stars are too faint. We study the sample of 335 Type II and ACs in the Small and Large MCls detected…
State-of-the art photometric measurements of extragalactic Cepheids account for the mean additional light due to chance superposition of Cepheids on crowded backgrounds through the use of artificial star measurements. However, light from…
We discuss the evolution of binaries with moderately high masses (about 10 - 30 solar masses), and with periods of about 3 - 300d, corresponding mostly to early Case B. These are usually thought to evolve either by reasonably conservative…
We report on the results of a comprehensive search for Cepheid variable stars in the fields photometricallymonitored by the OGLE Galaxy Variability Survey. We identify 742 Cepheids not included in the first release of the OGLE Collection of…