Photosphere Photosphere The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/"phos, photos" meaning "light" and σφαῖρα/"sphaira" meaning "sphere", in reference to it being a spherical surface that is perceived to emit light. It extends into a star's surface until the plasma becomes opaque, equivalent to an optical depth of approximately 2/3, or equivalently, a depth from which 50% of light will escape without being scattered. In other words, a photosphere is the deepest region of a luminous object, usually a star, that is transparent to photons of
Craig (given name) Craig (given name) Craig is a Scottish, Irish & Welsh masculine given name, all variations derive from the same Celtic branch. The name has two origins. In some cases it can originate from a nickname, derived from the Scottish Gaelic word "creag", meaning "rock," similar to Peter. In other cases, the given name originates from the Scottish surname "Craig", which is also derived from the same Scottish Gaelic word. Cognate forms of "creag" include the Irish "creig", Manx "creg", and Welsh "craig". The English word "crag" also shares an origin with these Celtic words. The given name "Craig" is popular