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We review our current knowledge of the solar chemical composition as determined from photospheric absorption lines. In particular we describe the recent significant revisions of the solar abundances as a result of the application of a…

Astrophysics · Physics 2015-06-24 Martin Asplund , Nicolas Grevesse , Jacques Sauval

Determining the properties of solar-like oscillating stars can be subject to many biases. A particularly important example is the helium-mass degeneracy, where the uncertainties regarding the internal physics can cause a poor determination…

Solar and Stellar Astrophysics · Physics 2021-11-24 Pierre S. Houdayer , Daniel R. Reese , Marie-Jo Goupil , Yveline Lebreton

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…

Astrophysics · Physics 2007-05-23 M. Asplund , N. Grevesse , M. Guedel , A. J. Sauval

We present evidence that the sound-speed variation with solar activity has a two-layer configuration, similar to the one observed below an active region, which consists of a negative layer near the solar surface and a positive one in the…

Solar and Stellar Astrophysics · Physics 2015-05-30 M. Cristina Rabello-Soares

Element settling inside the Sun now becomes detectable from the comparison of the observed oscillation modes with the results of the theoretical models. This settling is due, not only to gravitation, but also to thermal diffusion and…

Astrophysics · Physics 2009-10-30 Sylvie Vauclair

The quest of the knowledge of the structure and dynamics of the solar interior has been possible thanks to the study of the resonant acoustic (p) modes that are trapped in the solar interior. Since the solar rotation lifts the azimuthal…

Astrophysics · Physics 2008-11-03 R. A. Garcia

We report on an ongoing investigation into a seismic calibration of solar models designed for estimating the main-sequence age and a measure of the chemical abundances of the Sun. Only modes of low degree are employed, so that with…

Astrophysics · Physics 2009-11-13 G. Houdek , D. O. Gough

Today's picture of the internal solar rotation rate profile results essentially from helioseismic analyses of frequency splittings of resonant acoustic waves. Here we present another, complementary estimation of the internal solar rotation…

Solar and Stellar Astrophysics · Physics 2020-02-17 Ariane Schad , Markus Roth

We derive formulae connecting the frequency variations in the spectrum of solar oscillations to the dynamical quantities that are expected to change over the solar activity cycle. This is done for both centroids and the asymmetric part of…

Astrophysics · Physics 2009-11-10 W. A. Dziembowski , P. R. Goode

Primary inversions of accurately measured solar oscillation frequencies coupled with the equations of thermal equilibrium and other input physics, enable us to infer the temperature and hydrogen abundance profiles inside the Sun. These…

Astrophysics · Physics 2009-11-07 H. M. Antia , S. M. Chitre

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…

Solar and Stellar Astrophysics · Physics 2023-01-11 G. Buldgen , P. Eggenberger , A. Noels , R. Scuflaire , A. M. Amarsi , N. Grevesse , S. Salmon

Modelling the base of the solar convective envelope is a tedious problem. Since the first rotation inversions, solar modellers are confronted with the fact that a region of very limited extent has an enormous physical impact on the Sun.…

Recent 3D-simulations have shown that the turbulent kinetic flux (TKF) is significant. We discuss the effects of TKF on the size of convection zone and find that the TKF may help to solve the solar abundance problem. The solar abundance…

Solar and Stellar Astrophysics · Physics 2015-06-19 Q. S. Zhang

The Sun is an important calibrator for the theory of stellar structure and evolution. However, the accuracy of our solar evolution models is tightly linked to the physical ingredients that enter their computations. This include, amongst…

Solar and Stellar Astrophysics · Physics 2025-06-12 G. Buldgen , A. Noels , V. A. Baturin , J. Christensen-Dalsgaard , S. V. Ayukov , A. V. Oreshina , R. Scuflaire

We performed 3D numerical simulations of the solar surface wave field for the quiet Sun and for three models with different localized sound-speed variations in the interior with: (i) deep, (ii) shallow, and (iii) two-layer structures. We…

Solar and Stellar Astrophysics · Physics 2012-09-24 Konstantin V. Parchevsky , Junwei Zhao , Thomas Hartlep , Alexander G. Kosovichev

The solar interior is filled with turbulent thermal convection, which plays a key role in the energy and momentum transport and the generation of the magnetic field. The turbulent flows in the solar interior cannot be optically detected due…

Solar and Stellar Astrophysics · Physics 2024-10-10 Hiroyuki Masaki , Hideyuki Hotta

Using the code AUTOSTRUCTURE, extensive calculations of inner-shell atomic data have been made for the chemical elements He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Cr, Mn, Fe and Ni. The results are used to obtain up-dated opacities from…

It is well known that the observed amplitude of solar oscillations is lower in sunspots than in quiet regions of the Sun. We show that this local reduction in oscillation amplitudes combined with the phase-speed filtering procedure in…

Astrophysics · Physics 2009-11-11 S. P. Rajaguru , A. C. Birch , T. L. Duvall , M. J. Thompson , J. Zhao

An iterative method is presented for reconstructing the height-temperature profile of the solar atmosphere above a sunspot using multi-frequency spectro-polarimetric microwave observations. It is assumed that the emission is formed…

Solar and Stellar Astrophysics · Physics 2026-03-09 T. I. Kaltman , A. G. Stupishin , G. A. Makoev

Estimates of the bulk metal abundance of the Sun derived from the latest generation of model atmospheres are significantly lower than the earlier standard values. In Paper I we demonstrated that a low solar metallicity is inconsistent with…

Astrophysics · Physics 2009-10-06 M. H. Pinsonneault , Franck Delahaye