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.
Logan (given name) Logan (given name) The given name Logan is derived from the Scottish surname "Logan", which is in turn derived from a place name. The likely origin of this surname is a place located near Auchinleck, in Ayrshire. The place name is derived from the Scottish Gaelic "lagan", which is a diminutive of "lag", which in turn means "hollow". The given name is borne by males and females. The given name was the 17th most popular name for baby boys born in the United States in 2007 and was the 455th most popular name for baby girls born there in 2007.