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Related papers: First solar models with OPAS opacity tables

200 papers

The oscillation spectra of solar-type stars may in the not-too- distant future be used to constrain certain properties of the stars. The CD diagram of large versus small frequency separations is one of the powerful tools available to infer…

Astrophysics · Physics 2007-05-23 M. J. P. F. G. Monteiro , J. Christensen-Dalsgaard , M. J. Thompson

We present an attempt to reconcile the solar tachocline glitch, a thin layer immediately beneath the convection zone in which the seismically inferred sound speed in the Sun exceeds corresponding values in standard solar models, with a…

Solar and Stellar Astrophysics · Physics 2018-04-04 J. Christensen-Dalsgaard , D. O. Gough , E. Knudstrup

Helioseismic holography is an imaging technique used to study heterogeneities and flows in the solar interior from observations of solar oscillations at the surface. Holograms contain noise due to the stochastic nature of solar…

Solar and Stellar Astrophysics · Physics 2018-12-12 Laurent Gizon , Damien Fournier , Dan Yang , Aaron C. Birch , Hélène Barucq

The seismic study of the Sun and other stars offers a unique window into the interior of these stars. Thanks to helioseismology, we know the structure of the Sun to admirable precision. In fact, our knowledge is good enough to use the Sun…

Solar and Stellar Astrophysics · Physics 2016-10-19 Sarbani Basu

Dispersive delays due to the Solar wind introduce excess noise in high-precision pulsar timing experiments, and must be removed in order to achieve the accuracy needed to detect, e.g., low-frequency gravitational waves. In current pulsar…

By using a phenomenological field theory of nucleon-nucleon interactions, Oberhummer et al. found a cross section of p+p $\to$ d + e$^+$ + $\nu _e$ about 2.9 times that given by the potential approach and adopted in Standard Solar Model…

Astrophysics · Physics 2009-10-30 S. Degl'Innocenti , G. Fiorentini , B. Ricci

We construct seismic models of the four double-mode radial $\delta$ Scuti stars adopting opacities from three databases: OPAL, OP and OPLIB. The aim is to find the models that fit the observed frequencies of the two radial modes and have…

Intending to solve the decade old problem of solar opacity, we report substantial photoabsorption uncertainty due to the effect of ion-ion correlations. By performing detailed opacity calculations of the solar mixture, we find that taking…

Solar and Stellar Astrophysics · Physics 2018-03-01 Menahem Krief , Yair Kurzweil , Alexander Feigel , Doron Gazit

There are no good predictions for the amplitudes expected from solar-like oscillations in other stars. In the absence of a definitive model for convection, which is thought to be the mechanism that excites these oscillations, the amplitudes…

Astrophysics · Physics 2011-05-05 H. Kjeldsen , T. R. Bedding

This work presents a set of optimal machine learning (ML) models to represent the temporal degradation suffered by the power conversion efficiency (PCE) of polymeric organic solar cells (OSCs) with a multilayer structure…

Asteroseismology involves using the resonant frequencies of a star to infer details about its internal structure and evolutionary state. Oscillation frequencies are most useful when accompanied by accurate measurements of the more…

Astrophysics · Physics 2007-05-23 Timothy R. Bedding

Opacity is a key ingredient of stellar structure and evolution. In the present work, we recall the role of opacity in asteroseismology, focusing mainly on two kinds of astrophysical objects: $\beta$ Cephei-type stars, and the Sun. The…

Solar and Stellar Astrophysics · Physics 2019-04-30 Jean-Christophe Pain , Franck Gilleron

Understanding convection is important in stellar physics, for example as an input in stellar evolution models. Helioseismic estimates of convective flow amplitudes in deeper regions of the solar interior disagree by orders of magnitude…

Solar and Stellar Astrophysics · Physics 2021-05-12 Vincent G. A. Böning , Aaron C. Birch , Laurent Gizon , Thomas L. Duvall

We review some major open issues in the current modelling of low and intermediate mass, main sequence stars based on seismological studies. The solar case was discussed in a companion paper, here several issues specific to other stars than…

Solar and Stellar Astrophysics · Physics 2015-05-27 M. J. Goupil , Y. Lebreton , J. P. Marques , S. Deheuvels , O. Benomar , J. Provost

Despite the fact that the initial helium abundance is an essential ingredient in modelling solar-type stars, its abundance in these stars remains a poorly constrained observational property. This is because the effective temperature in…

Solar and Stellar Astrophysics · Physics 2021-01-20 Nuno Moedas , Benard Nsamba , Miguel T. Clara

In time-distance helioseismology, the time signals (Doppler shifts) at two points on the solar surface, separated by a fixed angular distance are cross-correlated, and this leads to a wave packet signal. Accurately measuring the travel…

Astrophysics · Physics 2011-02-11 R. Nigam , A. G. Kosovichev , P. H. Scherrer

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

Useful information from the inner layers of stellar pulsators may be derived from the study of their oscillations. In this paper we analyse three diagnostic tools suggested in the literature built from the oscillation frequencies computed…

Solar and Stellar Astrophysics · Physics 2015-05-19 I. M. Brandão , M. S. Cunha , O. L. Creevey , J. Christensen-Dalsgaard

Asteroseismology of solar-type stars has entered a new era of large surveys with the success of the NASA \textit{Kepler} mission, which is providing exquisite data on oscillations of stars across the Hertzprung-Russell (HR) diagram. From…

Convection is the mechanism by which energy is transported through the outermost 30% of the Sun. Solar turbulent convection is notoriously difficult to model across the entire convection zone where the density spans many orders of…

Solar and Stellar Astrophysics · Physics 2012-08-31 Laurent Gizon , Aaron C. Birch