Related papers: Measuring Solar Abundances with Seismology
Helioseismology has shown that the chemical composition of the Sun has changed over its lifetime. The surface abundance of helium and heavy elements is believed to have decreased by up to 10% relative to their initial values. However, this…
Understanding the governing mechanism of solar magnetism remains an outstanding challenge in astrophysics. Seismology is the most compelling technique with which to infer the internal properties of the Sun and stars. Waves in the Sun,…
The improvements of the observations of the solar system allowed by the use of probes and big instruments let appear several problems: The frequencies of the radio signals received from the probes sent over 5 UA from the Sun are too high;…
Implications of the recently discovered systematic abundance difference between the Sun and two collections of `solar twins' are discussed. The differences can be understood as an imprint on the abundances of the solar convection zone…
The solar diameter changes or not? Whatever will be the answer the methods used for its measurements are more and more challenging, and facing new astrophysical and optical problems since the required space resolution is of astrometric…
Solar oscillations frequencies show a distinct change with solar activity. The changes in frequencies can be used to study the time variation of solar structure. We discuss constraints on the changes in solar structure with time as obtained…
Normal modes are coupled by the presence of perturbations in the Sun, providing a novel and under-appreciated helioseismic technique with which to image the solar interior. The process of measuring coupling between normal modes is…
Observations of the Sun in the visible spectral range belong to standard measurements obtained by instruments both on the ground and in the space. Nowadays, both nearly continuous full-disc observations with medium resolution and dedicated…
The solar chemical composition is an important ingredient in our understanding of the formation, structure and evolution of both the Sun and our solar system. Furthermore, it is an essential reference standard against which the elemental…
The new generation of ground-based, large-aperture solar telescopes promises to significantly increase our capabilities to understand the many basic phenomena taking place in the Sun at all atmospheric layers and how they relate to each…
The high quality data provided by helioseismology, solar neutrino flux measurements, spectral determination of solar abundances, nuclear reactions rates coefficients among other experimental data, leads to the highly accurate prediction of…
The chemical composition of the Sun is requested in the context of various studies in astrophysics, among them in the calculation of the standard solar models (SSMs), which describe the evolution of the Sun from the pre-main-sequence to its…
The ratio of metal abundance to hydrogen abundance of the solar photosphere, $(Z/X)_{s}$, has been revised several times. Standard solar models, based on these revised solar abundances, are in disagreement with seismically inferred results.…
We review techniques for measuring stellar oscillations in solar-type stars. Despite great efforts, no unambiguous detections have been made. A new method, based on monitoring the equivalent widths of strong lines, shows promise but is yet…
Helioseismology, the study of global solar oscillations, has proved to be an extremely powerful tool for the investigation of the internal structure and dynamics of the Sun. Studies of time changes in frequency observations of solar…
The new solar composition, when applied to compute a model of the Sun, leads to serious disagreement between the predictions of the model and the observations obtained by helioseismology. New measurements of the coronal Ne/O abundance ratio…
The phenomena observed at the Sun have a variety of unique radio signatures that can be used to diagnose the processes in the solar atmosphere. The insights provided by radio obervations are further enhanced when they are combined with…
We present what constraints on opacities can be derived from the analysis of stellar pulsations of BA-type main-sequence stars. This analysis consists of the construction of complex seismic models which reproduce the observed frequencies as…
We present a quantitative estimate of the accuracy of the calculated diffusion coefficients, by comparing predictions of solar models with observational data provided by helioseismology. By taking into account the major uncertainties in…
Much of our understanding of the internal structure of the Sun derives from so-called standard theoretical solar models. Unfortunately, none of those models agrees completely with observation. The discrepancy is commonly associated with…