The solar energetic balance revisited by young solar analogs, helioseismology and neutrinos

TL;DR

This paper revisits the solar energetic balance by analyzing young solar analogs, helioseismology, and neutrino data to improve models of the Sun's evolution, energy loss, and internal structure, with implications for planetary formation.

Contribution

It introduces new models of the present Sun incorporating early mass loss and activity, addressing discrepancies in helioseismic sound speed profiles.

Findings

Estimated energy losses during the Sun's lifetime are a few percent.

Mass loss from young solar analogs could reach up to 30%.

About 20% of the sound speed discrepancy may stem from early solar phases.

Abstract

The energetic balance of the Standard Solar Model (SSM) results from an equilibrium between nuclear energy production, energy transfer, and photospheric emission. In this letter, we derive an order of magnitude of several % for the loss of energy in kinetic energy, magnetic energy, and X or UV radiation during the whole solar lifetime from the observations of the present Sun. We also estimate the mass loss from the observations of young solar analogs which could reach up to 30% of the current mass. We deduce new models of the present Sun, their associated neutrino fluxes, and their internal sound-speed profile. This approach sheds quantitative lights on the disagreement between the sound speed obtained by helioseismology and the sound speed derived from the SSM including the updated photospheric CNO abundances, based on recent observations. We conclude that about 20% of the present discrepancy could come from the incorrect description of the early phases of the Sun, its activity, its initial mass and mass-loss history. This study has obvious consequences on the solar system formation and the early evolution of the closest planets.