photosphère

CONT: Soleil. [...] Sa couche lumineuse, dont la température apparente est voisine de 6 000 K, et d'où provient la quasi totalité de la lumière solaire, est la photosphère parsemée de taches mobiles et entourée d'une atmosphère moins brillante, la chromosphère.
OBS: Sa surface apparente constitue le disque solaire.

CONT: photosphere ... it is a shell a few hundred miles in thickness marking the boundary between the dense interior gases of the sun and the more diffuse cooler gases in the outer portions of the sun.
CONT: The portion of the sun that we see in the sky, its visible surface, is called the ""photosphere"" (sphere of light) ... The photosphere is visible because it is the sun's outermost region, where the pressure is great enough and the temperature high enough to emit a continuous spectrum.