New Bands in the Electronic Band Spectrum of Neutral OH

Abstract

By producing a very rapid flow of water vapor through a discharge tube and high frequency excitation, it was possible to bring out portions of two new bands in the spectrum of neutral OH. These have been identified as the (3,0) and (3,1) bands. Faint lines have also been found between the lines of the $^{\mathrm{RR}}R_{21}$ singlet series of the $\ensuremath{\lambda}3064$ band. These lie where approximate calculations indicate that the $^{\mathrm{RR}}R_{21}$ branch of the (0,0) band of the isotope O${\mathrm{H}}^{2}$ should fall. The singlet series $^{\mathrm{RR}}R_{21}$ of the (2,0) band reported by Almy and Rahrer appears on our plates. There is also a group of nine lines extending from $\ensuremath{\lambda}2539$ to $\ensuremath{\lambda}2565$. This may be a portion of the (4,1) band but it has not been found possible to establish this definitely.