WΔu3−XΣg+1System ofN2

Bands of $W{}_{}{}^3{}_{}{}^{}\Delta _{\mu }^{}{}_{}{}^{}\leftarrow X{}_{}{}^1{}_{}{}^{}\Sigma _g^{+}{}_{}{}^{}$, a new system of molecular nitrogen, have been identified in absorption from their locations as predicted by the spectroscopic constants obtained in infrared emission. Three bands have been observed and measured, the (5, 0), (6, 0), and (7, 0). A Deslandres table with Franck-Condon factors is presented, which indicates that the system will occur most readily below 2500 Å. The relevant potential energy curves for the system are given with the observed transitions displayed.