Related papers: The evolutionary properties of intermediate-mass s…
We present a detailed study of the small frequency separations as diagnostics of the mass of the convective core and evolutionary stage of solar-type stars. We demonstrate how the small separations can be combined to provide sensitive tests…
The present paper reviews massive star (initial mass smaller than 120 M0) and very massive star (initial mass larger than 120 M0) evolution. I will focus on evolutionary facts and questions that may critically affect predictions of…
Most stars form in dense stellar environments. It is speculated that some dense star clusters may host intermediate-mass black holes (IMBHs), which may have formed from runaway collisions between high-mass stars, or from the mergers of less…
Two-dimensional models of rapidly rotating stars are already unavoidable for the interpretation of interferometric or asteroseismic data of this kind of stars. When combined with time evolution, they will allow the including of a more…
Newly formed stars are often observed to possess circumstellar disks, from which mass continues to be accreted onto the star and fed into outflowing jets, and which eventually may evolve into dusty debris disks and planetary systems. Recent…
An overview of selected topical problems on modelling oscillation properties in solar-like stars is presented. High-quality oscillation data from both space-borne intensity observations and ground-based spectroscopic measurements provide…
We present a review of the main phases of stellar evolution with particular emphasis on the nucleosynthesis and mixing mechanisms in low- and intermediate-mass stars. In addition to explicit studies of the effects of the first, second and…
The proximity to the Eddington luminosity has been attributed as the cause of several observed effects in massive stars. Computationally, if the luminosity carried through radiation exceeds the local Eddington luminosity in the low-density…
Mass loss from massive stars ($\ga 8 \msun$) can result in the formation of circumstellar wind blown cavities surrounding the star, bordered by a thin, dense, cold shell. When the star explodes as a core-collapse supernova (SN), the…
We analyze the impact on the Galactic nitrogen abundances of using a new set of low and intermediate mass star yields. These yields have a significant yield of primary nitrogen from intermediate mass stars. We use these yields as an input…
A review on current observations of high-mass star formation is given, with a little bit of theoretical background. Particular emphasis is given to the, in my opinion, most important observations to put strong constraints on models of…
The rotation of horizontal branch stars places important constraints on angular momentum evolution in evolved stars and therefore rotational mixing on the giant branch. Prompted by new observations of rotation rates of horizontal branch…
During the evolution of a pulsar, various phase transitions may occur in its dense interior, such as superfluid transition, as well as transition to various exotic phases of quantum chromodynamics (QCD). We propose a technique which allows…
Massive star formation requires the accretion of gas at high rate while the star is already bright. Its actual luminosity depends sensitively on the stellar structure. We compute pre-main-sequence tracks for massive and intermediate-mass…
Studies of the rotational velocities of intermediate-mass main-sequence stars are crucial for testing stellar evolution theory. They often rely on spectroscopic measurements of the projected rotation velocities. These not only suffer from…
There is currently much interest in the possible presence of intermediate-mass black holes in the cores of globular clusters. Based on theoretical arguments and simulation results it has previously been suggested that a large core radius --…
Molecular clouds are the principle stellar nurseries of our universe, keeping them in the focus of both observational and theoretical studies. From observations, some of the key properties of molecular clouds are well known but many…
We present the Pre-Main-Sequence (PMS) evolutionary tracks of stars with 0.0065~5.0Ms. The models were evolved from the PMS stellar birthline to the onset of hydrogen burning in the core. The convective turnover timescales which enables an…
Studies of evolved massive stars indicate that they form in a clustered mode. During the earliest evolutionary stages, these regions are embedded within their natal cores. Here, we show high-spatial-resolution interferometric dust continuum…
We present extensive evolutionary models of stars with initial zero-metallicity, covering a large range of initial masses (i.e. 0.7 <= M <= 100 Msun). Calculations are carried out at constant mass, with updated input physics, and applying…