paper

Temperature and density profiles in the corona of main-sequence stars induced by stochastic heating in the chromosphere

arXiv:2411.07868 · doi:10.1051/0004-6361/202452879

Abstract

All but the most massive main-sequence stars are expected to have a rarefied and hot (million-Kelvin) corona like the Sun. How such a hot corona is formed and supported has not been completely understood yet, even in the case of the Sun. Recently, Barbieri et al. (A&A 2024, J. Plasma Phys. 2024) introduced a new model of a confined plasma atmosphere and applied it to the solar case, showing that rapid, intense, intermittent and short-lived heating events in the high chromosphere can drive the coronal plasma into a stationary state with temperature and density profiles similar to those observed in the solar atmosphere. In this paper we apply the model to main-sequence stars, showing that it predicts the presence of a solar-like hot and rarefied corona for all such stars, regardless of their mass. However, the model is not applicable as such to the most massive main-sequence stars, because the latter lack the convective layer generating the magnetic field loop structures supporting a stationary corona, whose existence is assumed by the model. We also discuss the role of stellar mass in determining the shape of the temperature and density profiles.

11 pages, 16 figures. Submitted to Astronomy and Astrophysics. Comments welcome

References in corpus (8)

Cited by in corpus (3)