Photosphere but more tenuous corona. Other "surface features" on the photosphere are solar flares and sunspots. 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
Shell plating Shell plating Shell plating is the outer-most structure on the hull of a steel or aluminum ship or boat. A strake is the name given to each line of planking in a wooden vessel. In modern ship construction it refers to the longitudinal run of plating covering the hull, deck and bulkhead structure. Certain specific strakes are uniquely identified: Keel: is a special strake of the Bottom plating extending from the centerplane outboard. Bottom: the Bottom Shell plate strakes extend from the Keel to the Bilge. Bilge: is the plating which transitions from the more-or-less horizontal Bottom Shell to the