Nonlinear Alfvén Wave Model of Stellar Coronae and Winds from the Sun to M Dwarfs
Abstract
An M dwarf's atmosphere and wind are expected to be highly magnetized. The nonlinear propagation of Alfvén waves could play a key role in both heating the stellar atmosphere and driving the stellar wind. Using this Alfvén wave scenario, we carried out a one-dimensional compressive magnetohydrodynamic simulation to examine the nonlinear propagation of Alfvén waves from the M dwarf's photosphere, chromosphere to the corona, and interplanetary space. Based on the simulation results, we developed a semi-empirical method describing the solar and M dwarf's coronal temperature, stellar wind velocity, and wind's mass-loss rate. We find that M dwarfs' coronae tend to be cooler than the solar corona, and that M dwarfs' stellar winds can be characterized as having a faster velocity and much smaller mass-loss rate compared to those of the solar wind.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 2021
- DOI:
- arXiv:
- arXiv:2012.10868
- Bibcode:
- 2021ApJ...906L..13S
- Keywords:
-
- Stellar winds;
- Stellar coronae;
- Stellar chromospheres;
- M dwarf stars;
- Alfven waves;
- Magnetohydrodynamics;
- 1636;
- 305;
- 230;
- 982;
- 23;
- 1964;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 12 pages, 5 figures, accepted for the publication in The Astrophysical Journal Letters