Related papers: The Pre-main Sequence: Challenges and Prospects fo…

We demonstrate that a seismic analysis of stars in their earliest evolutionary phases is a powerful method to identify young stars and distinguish their evolutionary states. The early star that is born from the gravitational collapse of a…

Asteroseismology has been proven to be a successful tool to unravel details of the internal structure for different types of stars in various stages of their main sequence and post-main sequence evolution. Recently, we found a relation…

Massive stars are important metal factories in the Universe. They have short and energetic lives, and many of them inevitably explode as a supernova and become a neutron star or black hole. In turn, the formation, evolution and explosive…

The dissertation presents result from study of Pre-main sequence (PMS) stars that are in the earliest stages of stellar evolution. These young stellar objects are still in the process of formation, and the energy they emit is produced only…

Young A-type stars in the pre--main-sequence (PMS) evolutionary phase are particularly interesting objects since they cover the mass range (1.5-4 solar ma sses) which is most sensitive to the internal conditions inherited during the…

Massive stars play a major role not only in stellar evolution but also galactic evolution theory. This is because of their dynamical interaction with binary companions, and because their strong winds and explosive deaths as supernovae…

Asteroseismology provides powerful means to probe stellar interiors. The oscillations frequencies are closely related to stellar interior properties via the density and sound speed profiles. Since these are tightly linked with the mass and…

During the last few decades, great effort has been made towards understanding hydrodynamical processes which determine the structure and evolution of stars. Up to now, the most stringent constraints have been provided by helioseismology and…

Asteroseismology, as a tool to use the indirect information contained in stellar oscillations to probe the stellar interiors, is an active field of research presently. Stellar age, as a fundamental property of star apart from its mass, is…

Context: The pre-main sequence evolution is often simplified by choosing classical initial models. These have large initial radii and sufficient uniform contraction to make them fully convective. Contrary to that, real stars are born as…

The last decade has witnessed significant advances in our observational understanding of the earliest stages of low-mass star formation. The advent of sensitive receivers on large radio telescopes such as the JCMT and IRAM 30m MRT has led…

We provide a status report on the determination of stellar ages from asteroseismology for stars of various masses and evolutionary stages. The ability to deduce the ages of stars with a relative precision of typically 10 to 20% is a unique…

Asteroseismology has grown from its beginnings three decades ago to a mature field teeming with discoveries and applications. This phenomenal growth has been enabled by space photometry with precision $10-100$ times better than ground-based…

Our current understanding of the physical processes of star formation is reviewed, with emphasis on processes occurring in molecular clouds like those observed nearby. The dense cores of these clouds are predicted to undergo gravitational…

The first asteroseismic studies of pre-main sequence (pre-MS) pulsators have been conducted based on data from the space telescopes MOST and CoRoT with typical time bases of less than 40 days. With these data, a relation between the…

The early stages of the pre-Main-Sequence (PMS) evolution of young stars are characterized by a substantial interaction between the central star and the surrounding disk. Among the processes that take place, the accretion of material from…

Asteroseismology is the study of the interior physics and structure of stars using their pulsations. It is applicable to stars across the Hertzsprung-Russell (HR) diagram and a powerful technique to measure masses, radii and ages, but also…

Yearslong time series of high-precision brightness measurements have been assembled for thousands of stars with telescopes operating in space. Such data have allowed astronomers to measure the physics of stellar interiors via nonradial…

Stellar evolution, a fundamental bedrock of modern astrophysics, is driven by the physical processes in stellar interiors. While we understand these processes in general terms, we lack some important ingredients. Seemingly small…

The physical mechanisms that set the initial rotation rates in massive stars are a crucial unknown in current star formation theory. Observations of young, massive stars provide evidence that they form in a similar fashion to their low-mass…