Photosphere

The photosphere is a star's outer shell from which light is radiated. It extends into a star's surface until the plasma becomes opaque, equivalent to an optical depth of approximately 2⁄3,^[1] or equivalently, a depth from which 50% of light will escape without being scattered.

A photosphere is the region of a luminous object, usually a star, that is transparent to photons of certain wavelengths.