It is a remarkable and fascinating fact that a solitary star like the Sun emits intense X-rays from its outer atmosphere.Observations with the Japan-US Yohkoh satellite (Tsuneta et al. 1991) showed that all the sporadic heating from major flares to ubiquitous tiny bursts in the solar corona is due to magnetic reconnection – a process that efficiently annihilates magnetic fields with opposite direction and generating heat,jets and non-thermal acceleration. Magnetic fields do dissipate in the corona with a time scale 1012 faster than that of the classical Ohmic dissipation. Although this leads to an attractive conjecture that the solar corona in general is heated by an ensemble of tiny bursts (Katsukawa et al. 2009 and references therein), the precise mechanism for heating the solar corona and for the solar wind acceleration mechanism is not known.
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