MHD thermal instabilities in cool inhomogeneous atmospheresThe formation of a coronal state in a stellar atmosphere is investigated. A numerical code is used to study the effects of atmospheric gradients and finite loop dimension on the scale of unstable perturbations, solving for oscillatory perturbations as eigenfunctions of a boundary value problem. The atmosphere is considered as initially isothermal, with density and pressure having scale heights fixed by the hydrostatic equations. Joule mode instability is found to be an efficient mechanism for current filamentation and subsequent heating in initially cool atmospheres. This instability is mainly effective at the top of magnetic loops and is not suppressed by thermal conduction.
Document ID
19830066329
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Bodo, G. (Osservatorio Astronomico Turin, Italy)
Ferrari, A. (CNR, Istituto di Cosmo-Geofisica; Torino, Universita Turin, Italy)
Massaglia, S. (Torino, Universita Turin, Italy)
Rosner, R. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Date Acquired
August 11, 2013
Publication Date
January 1, 1983
Subject Category
Astrophysics
Meeting Information
Meeting: Activity in red-dwarf stars; Seventy-first Colloquium