We thank J. Toomre for useful comments on improving the presentation of the paper, and W. Däppen for providing energy-level tables for use in calculating the MHD equation of state. We also want to thank the referee of this paper, S. Turck-Chièze, who suggested other useful improvements. This work is supported in part by the National Aeronautics and Space Administration through grants NAG5-2256 and NAG5-3077.
© European Southern Observatory (ESO) 1998
Online publication: May 15, 1998