Shell star Shell star A shell star is a star having a spectrum that shows extremely broad absorption lines, plus some very narrow absorption lines. They typically also show some emission lines, usually from the Balmer series but occasionally of other lines. The broad absorption lines are due to rapid rotation of the photosphere, the emission lines from an equatorial disk, and the narrow absorption lines are produced when the disc is seen nearly edge-on. Shell stars have spectral types O7.5 to F5, with rotation velocities of 200–300 km/s, not far from the point when the rotational acceleration would disrupt the star.
Raven (given name) Raven (given name) Raven is a unisex given name in the English language. In the United States of America, the name is more commonly used as a feminine name, and has ranked amongst the top 1,000 feminine names given to baby girls since 1977. The name originates from the English vocabulary word "raven", which in turn is ultimately derived from the Old English "hræfn". As a masculine name, "Raven" parallels the Old Norse "Hrafn", and the Old English "*Hræfn", which both mean "raven". As a feminine name, "Raven" is among several other names derived from birds; names such as "Dove",