Related papers: Light elements in massive single and binary stars
Massive stars play a key role in the evolution of the Universe. Our goal is to compare observed and predicted properties of single Galactic O stars to identify and constrain uncertain physical parameters and processes in stellar evolution…
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.…
The evolution of massive stars in general, massive close binaries in particular depend on processes where, despite many efforts, the physics are still uncertain. Here we discuss the effects of stellar wind as function of metallicity during…
The majority of massive stars live in binary or multiple systems and will interact during their lifetimes, which helps to explain the observed diversity of core-collapse supernovae. Donor stars in binary systems can lose most of their…
Photoionized nebulae comprise basically HII regions and planetary nebulae, and their abundances give important clues on the nucleosynthesis and chemical evolution of their host galaxies. There is presently a large amount of data on these…
Binary stars evolve differently from single stars, thus binary evolution is very useful for astrophysical studies. This paper discusses the application of binary evolution in the studies of stars, star clusters, galaxies, and cosmology. In…
Planetary nebulae are traditionally considered to represent the final evolutionary stage of all intermediate-mass stars ($\sim$0.7-8Msol). Recent evidence seems to contradict this picture. In particular, since the launch of the Hubble Space…
Half or more of stars more massive than our Sun are orbited by a companion star in a binary system. Many binaries have short enough orbits that the evolution of both stars is greatly altered by an exchange of mass and angular momentum…
Studies of beryllium abundance in large samples of solar-type stars show a small fraction of extremely beryllium-deficient stars, which challenges our current understanding of light element depletion in these stars. We suggest two possible…
Recent detailed simulations of Galactic Chemical Evolution have shown that the heavy elements, in particular [Fe/H], are expected to exhibit a weak, or absent, correlation with stellar ages in the early Galaxy due to the lack of efficient…
The evolution of single stars at low metallicity has attracted a large interest, while the effect of metallicity on binary evolution remains still relatively unexplored. We study the effect of metallicity on the number of binary systems…
The impact of new stellar evolution models with rotation on the predictions of population synthesis models is discussed. Massive rotating stars have larger convective cores than their non-rotating counterparts, and their outer layers are…
Ap/Bp stars are magnetic chemically peculiar early A and late B type stars of the main sequence. They exhibit peculiar surface abundance anomalies that are thought to be the result of gravitational settling and radiative levitation. The…
Dynamical interactions that take place between objects in dense stellar systems lead to frequent formation of exotic stellar objects, unusual binaries, and systems of higher multiplicity. They are most important for the formation of…
There are obvious and direct ways in which the presence of binary companions may affect activity in OB stars through tidal interactions. In this review, however, I consider a more fundamental role for multiplicity and explore claims that…
Rotation deeply affects the evolution of very metal poor massive stars. Indeed, even moderately rotating stars reach the break--up limit during the Main--Sequence (MS) phase, they evolve rapidly to the red after the core H--burning phase…
Rapidly rotating stars are readily produced in binary systems. An accreting star in a binary system can be spun up by mass accretion and quickly approach the break-up limit. Mergers between two stars in a binary are expected to result in…
Li abundances in the bulk of low-mass metal-poor stars are well reproduced by stellar evolution models adopting a constant initial abundance. However, a small number of stars have exceptionally high Li abundances, for which no convincing…
Among the emission-line stars, the classical Be stars known for their extreme properties are remarkable. The Be stars are B-type main sequence stars that have displayed at least once in their life emission lines in their spectrum. Beyond…
We discuss the internal structure of stars in the mass range 1.5 to 4 M_sun from the PMS to the subgiant phase with a particular emphasis on the convective core and the convective superficial layers. Different physical aspects are…