OBSERVATION OF THE TRANSITION IN O2

The Q branch of the (0,0) band of the electric quadrupole [Formula: see text] transition in O2 has been observed at 1.908 μ in the emission spectrum of a discharge through O2 and He. By a comparison with the (0,0) atmospheric O2 band [Formula: see text], the absolute transition probability for the (b–a) system has been found to be 2.5 × 10−3 sec−1, with an uncertainty of a factor of 2. The (0,0) band of the infrared atmospheric [Formula: see text] system of O2 has also been observed in emission. Using the observed intensity of the (0,1) atmospheric O2 band in the aurora and airglow one may predict that the (0,0) (b–a) band should be detectable in a strong aurora if observations are made from high altitude.