Rotational Analysis of the First-Negative Bands of the CO+Molecule

By using the light of a graphite hollow cathode in a C${\mathrm{O}}_2$ atmosphere, the ${}_{}{}^2{}_{}{}^{}\Sigma \to {}_{}{}^2{}_{}{}^{}\Sigma$ (first-negative) C${\mathrm{O}}^{+}$ bands at $\lambda \lambda 2299.7$, 2325.2, 2419.4, 2445.8, 2474.2, 2504.5, 2577.7, 2607.2, 2638.7 and 2672.3A have been photographed in the second and third order of a 21 foot Rowland grating. The analysis gives the rotational constants: ${B_e}^{\prime }=1.778\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$, ${\alpha }^{\prime }=0.032\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$ and ${B_e}^{\prime \prime }=1.954\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$, ${\alpha }^{\prime \prime }=0.019\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$. The $\rho$-type doubling of both of the upper and lower ${}_{}{}^2{}_{}{}^{}\Sigma$ states seems to be very small. Only lines with high rotational quantum numbers show broadenings and sometimes measurable doublings. Definite perturbations could not be observed.