OBSERVATION OF THE (0,1) CN BAND IN THE CARBON ARC

$^{1}$ Astroph. J. 108, 163 (1948) $^{2}$ Astroph. J. 109, 551 (1949)Author Institution: National Bureau of StandardsThe red system of $^{2}\pi^{-^{2}} \Sigma$ bands of CN were found to have sequences beyond $1.0\mu$ by Herzberg and $Phillips^{1}$ who published a new assignment of vibrational quantum numbers. These bands appear with great intensity in emission in arcs between carbon or graphite electrodes. The wavelengths of the band heads of the (0,0) sequence near 10900 \AA were measured by $Kiess.^{2}$ Both the (0,0) and (0,1) sequences have been observed with high resolution in the course of observations of infrared emission spectra, using 20-ampere carbon arcs in air. Approximately 400 resolved lines of the (0,1) sequence have been observed. Prominent and easily recognizable features include not only the four band heads, $R_{21}, R_{2}, R_{1}$, and $Q_{1}$, but also most of the individual rotational lines of the $R_{1}, R_{2}, Q_{1}, Q_{2}, P_{1}$, and $P_{2}$ branches. The analysis is in progress