Related papers: Rotational Mixing in Magellanic Clouds B Stars - T…
The effects of rapid rotation on stellar evolution can be profound. We are now beginning to gather enough data to allow a realistic comparison between different physical models. Two key tests for any theory of stellar rotation are first…
Observational evidence has continued to mount that a significant fraction of rapidly rotating early-B type stars are products of binary mass transfer. However, very few mid- and late-type B stars with rapid rotation have been demonstrated…
Many young and intermediate age massive stellar clusters host bimodal distributions in the rotation rates of their stellar populations, with a dominant peak of rapidly rotating stars and a secondary peak of slow rotators. The origin of this…
Context. Light elements and nitrogen surface abundances together can constrain the mixing efficiencies in massive stars on the main sequence, because moderate mixing at the surface leads to a depletion of light elements but only later to an…
Two recent observing campaigns provide us with moderate dispersion spectra of more than 230 cluster and 370 field B stars. Combining them and the spectra of the B stars from our previous investigations ($\sim$430 cluster and $\sim$100 field…
Aims: Recent observations have challenged our understanding of rotational mixing in massive stars by revealing a population of fast-rotating objects with apparently normal surface nitrogen abundances. However, several questions have arisen…
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…
We use our new population synthesis code BONNFIRES to test how surface abundances predicted by rotating stellar models depend on the numerical treatment of rotational mixing, such as spatial resolution, temporal resolution and computation…
We present the results of a study aimed at investigating the effects of dynamical evolution on the spatial distribution and mixing of primordial binary stars in multiple-population globular clusters. Multiple stellar population formation…
We present an analysis of high-resolution FLAMES spectra of approximately 50 early B-type stars in three young clusters at different metallicities, NGC6611 in the Galaxy, N11 in the Large Magellanic Cloud (LMC) and NGC346 in the Small…
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…
The nitrogen to carbon (N/C) and nitrogen to oxygen (N/O) ratios are the most sensitive quantities to mixing in stellar interiors of intermediate and massive stars. We further investigate the theoretical properties of these ratios as well…
Rotation has a number of important effects on the evolution of stars. Apart from structural changes because of the centrifugal force, turbulent mixing and meridional circulation caused by rotation can dramatically affect a star's chemical…
We investigate the surface nitrogen content of the six magnetic O stars known to date as well as of the early B-type star tau Sco. We compare these abundances to predictions of evolutionary models to isolate the effects of magnetic field on…
Rotational variables are stars that vary in brightness due to star spots modulated by rotation. They are probes of stellar magnetism, binarity, and evolution. Phillips et al. (2023) explored distinct populations of ~50,000 high-amplitude…
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…
Many stars, including those in binary or multiple systems, exhibit modified rotational evolution due to tidal interactions. While magnetic braking slows rotation in single stars, close binaries experience synchronization from tidal forces,…
Around the turn of the last century, star clusters of all kinds were considered "simple" stellar populations. Over the past decade, this situation has changed dramatically. At the same time, star clusters are among the brightest stellar…
Beryllium and oxygen abundances have been derived in a sample of F-type field stars for which lithium abundances had been measured previously, with the aim of obtaining observational constraints to discriminate between the different mixing…
In this paper we study the effects of rotation in low-mass, low-metallicity RGB stars. We present the first evolutionary models taking into account self-consistently the latest prescriptions for the transport of angular momentum by…