On the Spark Spectrum of Oxygen (O II)

Abstract

Thirteen new terms in the O II spectrum have been definitely, and two more provisionally, identified, accounting for 99 lines, including all the strong ones not previously classified. The electron configurations corresponding to the new terms have been identified. Those in which the excited electron is in a $4f$ or $5f$ orbit give diffuse lines. Intercombinations between the doublet and quartet systems (detected independently by Croze and Mihul) confirm Bowen's conclusions regarding the origin of the nebular lines near $\lambda 3727$.