Related papers: Determining solar abundances using helioseismology
The compositions of stars are a critical diagnostic tool for many topics in astronomy such as the evolution of our Galaxy, the formation of planets, and the uniqueness of the Sun. Previous spectroscopic measurements indicate a large…
In helioseismology, there is a well-known offset between observed and computed oscillation frequencies. This offset is known to arise from improper modeling of the near-surface layers of the Sun, and a similar effect must occur for models…
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…
The Sun is the most studied of all stars. It is a reference for all other observed stars and a laboratory of fundamental physics helping us understand processes occuring in conditions irreproducible on Earth. However, our understanding of…
The purpose of this work is to describe the assumptions built into the X-ray spectrum fitting software XSPEC for the calculation of element abundances and emission measure of a plasma and to describe the effects when those assumptions are…
In the last decade, the photospheric abundances of the Sun had been revised several times by many observers. The standard solar models (SSM) constructed with the new low-metal abundances disagree with helioseismic results and detected…
Solar oscillations consist of a rich spectrum of internal acoustic waves and surface gravity waves, stochastically excited by turbulent convection. They have been monitored almost continuously over the last ten years with high-precision…
The present-day abundance of beryllium in the solar atmosphere provides clues about mixing mechanisms within stellar interiors. However, abundance determinations based on the Be II 313.107 nm line are prone to systematic errors due to…
Standard solar models (SSM) are facing nowadays a new puzzle: the solar composition problem. New determinations of solar metal abundances lead SSM calculations to conflict with helioseismological measurements, showing discrepancies that…
In this paper, we examine a new updated solar model taking advantage of recent reexamination of the nuclear reactions rates and of the microscopic diffusion of helium and heavy elements. Our best model fits the helioseismic data reasonably…
We derive the abundance of 19 elements in a sample of 64 stars with fundamental parameters very similar to solar, which minimizes the impact of systematic errors in our spectroscopic 1D-LTE differential analysis, using high-resolution…
Abundances of elements comprising solar energetic particles (SEPs) come with two very different patterns. Historically called "impulsive" and "gradual" events, they have been studied for 40 years, 20 years by the Wind spacecraft. Gradual…
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…
As the most abundant element in the universe after hydrogen and helium, oxygen plays a key role in planetary, stellar, and galactic astrophysics. Its abundance is especially influential on stellar structure and evolution, and as the…
Motivated by the solar composition problem and by using the recently developed Linear Solar Model approach, we analyze the role of opacity and metals in the sun. After a brief discussion of the relation between the effects produced by a…
We study the diffusion of helium and other heavy elements in the solar interior by solving exactly the set of flow equations developed by Burgers for a multi-component fluid, including the residual heat-flow terms. No approximation is made…
Context: Helioseismology aims to infer the properties of the solar interior by analyzing observations of acoustic oscillations. The interpretation of the helioseismic data is however complicated by the non-trivial relationship between…
While it has been relatively easy to determine solar-cycle related changes in solar dynamics, determining changes in structure in the deeper layers of the Sun has proved to be difficult. By using helioseismic data obtained over two solar…
Highly-differential spectroscopic studies have revealed that the Sun is deficient in refractory elements relative to solar twins. To investigate the role of giant planets on this signature, we present a high precision abundance analysis of…
Context. The Sun acts as a cornerstone of stellar physics. Thanks to spectroscopic, helioseismic and neutrino flux observations, we can use the Sun as a laboratory of fundamental physics in extreme conditions. The conclusions we draw are…