You won't find the Temperature of the sun on Wikipedia.
This isn't a mystery, as nobody actually knows the temperature of the sun.
Not that there isn't a lot of speculation and information about the sun, and the various temperatures involved.
The center might be around 15,700,000 kelvin, the Photosphere we are pretty sure about is exactly 5,778 kelvin, and the Corona around 5,000,000 kelvin. (which means the temperature rises as you leave the surface, a lot)
This all has to be true, because it is on the Wikipedia article.
It still doesn't tell us the temperature of the sun. But this is understandable. as nobody knows the temperature of the Earth either.