Shell star variables. Pleione and Gamma Cassiopeiae itself are both variable stars that have intermittent shell episodes where strong shell features appear in the spectrum and the brightness increases or decreases significantly. At other times the shell is not detectable in the spectrum, and even the emission lines may disappear. 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,
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