Issue |
A&A
Volume 694, February 2025
|
|
---|---|---|
Article Number | A154 | |
Number of page(s) | 11 | |
Section | Stellar atmospheres | |
DOI | https://doi.org/10.1051/0004-6361/202452879 | |
Published online | 11 February 2025 |
Temperature and density profiles in the corona of main-sequence stars induced by stochastic heating in the chromosphere
1
Dipartimento di Fisica e Astronomia, Università di Firenze,
via G. Sansone 1,
50019
Sesto Fiorentino,
FI,
Italy
2
LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris-Cité,
5 place Jules Janssen,
92195
Meudon,
France
3
INAF – Osservatorio Astrofisico di Arcetri,
Largo E. Fermi 5,
50125
Firenze,
Italy
4
INFN, Sezione di Firenze,
via G. Sansone 1,
50019
Sesto Fiorentino,
FI,
Italy
★ Corresponding author; luca.barbieri@obspm.fr
Received:
4
November
2024
Accepted:
20
January
2025
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, a new model of a confined plasma atmosphere has been introduced and applied 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.
Key words: plasmas / methods: analytical / Sun: atmosphere / Sun: corona / stars: atmospheres / stars: coronae
© The Authors 2025
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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