lalonde ha scritto:
Dire che le temperature delle stelle aumentano dirigendosi verso il nucleo è parecchio azzardato. La corona solare, ovvero la parte esterna alla superficie raggiunge la temperatura di 1.000.000 milione di gradi, mentre la superficie solare raggiunge mediamente i 6000 k.

citazione da Wikipedia
Citazione:

The optical surface of the Sun (the photosphere) is known to have a temperature of approximately 6,000 K. Above it lies the solar corona at a temperature of 1,000,000 K. The high temperature of the corona shows that it is heated by something other than direct heat conduction from the photosphere.It is thought that the energy necessary to heat the corona is provided by turbulent motion in the convection zone below the photosphere, and two main mechanisms have been proposed to explain coronal heating. The first is wave heating, in which sound, gravitational and magnetohydrodynamic waves are produced by turbulence in the convection zone. These waves travel upward and dissipate in the corona, depositing their energy in the ambient gas in the form of heat. The other is magnetic heating, in which magnetic energy is continuously built up by photospheric motion and released through magnetic reconnection in the form of large solar flares and myriad similar but smaller events.[17]

Currently, it is unclear whether waves are an efficient heating mechanism. All waves except Alfvén waves have been found to dissipate or refract before reaching the corona.[18] In addition, Alfvén waves do not easily dissipate in the corona. Current research focus has therefore shifted towards flare heating mechanisms. One possible candidate to explain coronal heating is continuous flaring at small scales,[19] but this remains an open topic of investigation.

Per spiegare tutto ciò i fisici si stanno arrampicando sugli specchi....direi che è un argomento cruciale. La nostra cara e vecchia(?) stella....quanto poco ne sappiamo^^

Edit: Scusa Ivan, ho visto solo ora che avevi già postato qualcosa a proposito. Sarebbe interessante una discussione sulla teoria dell'universo elettrico....se ne vedrebbero delle belle^^