Rotational Analysis of Some CO2Emission Bands. Part I

By using the light of a hollow cathode discharge and that of a Back box with direct current, the red degraded C${\mathrm{O}}_2$ bands at $\lambda \lambda 3247$, 3254, 3370, 3377, 3503, 3511, 3534, 3545, 3674 and 3839A have been photographed in the third order of a 21 foot Rowland grating and analyzed. The bands are composed of $P$ and $R$ branches and on first inspection they show no alternately missing lines. The lines of the bands at $\lambda \lambda 3254$, 3377, 3511, 3534, and 3839A show staggering, while the lines of the other bands do not (in the limit of observational accuracy). The single structure of the bands indicates that the molecule is linear in both initial and final states. The distance between the carbon and an oxygen atom computed from the rotational constants is almost the same as computed from the CO and C${\mathrm{O}}^{+}$ bands. The above enumerated bands show no Zeeman effect of the observable lines. Other bands which are found to show more complicated structure and Zeeman effect will be the subject of further investigations.