What is the temperature of plasma in the stars?
The whole of any star (& its environs) have matter in neither Solid, Liquid nor Gas states but in various ‘Plasma’ states. This nomenclature is unfortunate because it is not in human experience to percieve or imagine that state of matter. So we don’t have names or these states (see Wiki). Only clue for us humans is the ‘flame’ that is a very low level Plasma state, briefly seen on Earth. It is only because of Scientists’ efforts that we are being made aware of Star’s interiors, Plasma states that is all the more common and ‘universal’, to the exclusion of Solid-Liquid-Gas thing. In the interior the tempearature attains a maximum at the core. Sun is a typical example of (not so big, not so small or not so dazzling bright, not so dim & red) a star. Its Core is at 16 million degrees for the Sun. For brighter stars it may crawl towards billion degrees. Again these are all based on lot of conjectures and estimates resting on solid scientific facts. Alfven, Schwartzchild & Chandrasekhar are
A star doesn’t have the same temperature throughout. At the surface, the temperature can be determined by the Wien displacement law by assuming it behaves as a black body, with a corresponding emission distribution. For the Sun, that’s about 5800 degrees Kelvin, or about 5600 degrees Celsius. The core temperature will depend on the hydrostatic balance between the nuclear reactions at the center (which depends on what is being fused, e.g. hydrogen, helium, carbon, …) and the actual mass column. For our Sun, the temperature comes from fusing hydrogen. It takes a few kilo-electron-Volt to overcome the Coulomb potential barrier repelling two nuclei, so that means that you need upwards of 10 million Kelvin (1 eV scales with about 10^4 Kelvin).
