Note on the spectrum of μ centauri.

An investigation of Pickering’s reproduction of this spectrum— which apparently consists of the spectrum of an Orion star + bright hydrogen lines and certain other bright lines of minor intensity- suggested that the latter are radiation lines corresponding to some of the stronger absorption lines ofα Cygni. Theseα Cygni lines have previously been attributed to the enhanced lines of certain metals, chiefly Fe, Ti, Cr, Mg, and Si. A close investigation has now shown that nearly all the most marked bright lines inμ Centauri—other than those of hydrogen—occupy positions closely corresponding to those of the most conspicuous enhanced lines of iron. The wave-lengths of some of the brightu Centauri lines are compared with those of the enhanced lines of iron andα Cygni lines in the table at the end of this note. The close agreement is very noticeable.