Closed and open magnetic fields in stellar winds

Abstract

view Abstract Citations (11) References (15) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Closed and open magnetic fields in stellar winds Mullan, D. J. ; Steinolfson, R. S. Abstract A numerical study of the interaction between a thermal wind and a global dipole field in the sun and in a giant star is reported. In order for closed field lines to persist near the equator (where a helmet-streamer-like configuration appears), the coronal temperature must be less than a critical value Tc, which scales as M/R. This condition is found to be equivalent to the following: for a static helmet streamer to persist, the sonic point above the helmet must not approach closer to the star than 2.2-2.6 stellar radii. Implications for rapid mass loss and X-ray emission from cool giants are pointed out. The results strengthen the case for identifying empirical dividing lines in the H-R diagram with a magnetic topology transition locus (MTTL). Support for the MTTL concept is also provided by considerations of the breakdown of magnetostatic equilibrium. Publication: The Astrophysical Journal Pub Date: March 1983 DOI: 10.1086/160830 Bibcode: 1983ApJ...266..823M Keywords: Giant Stars; Magnetic Field Configurations; Solar Magnetic Field; Stellar Coronas; Stellar Magnetic Fields; Stellar Winds; Hertzsprung-Russell Diagram; Magnetohydrodynamic Flow; Plasma Interactions; Stellar Mass Ejection; Stellar Temperature; X Ray Astronomy; Astrophysics full text sources ADS |