Knowledge Bank

The vacuum ultraviolet absorption spectrum of carbon monoxide has been observed under high resolution in the 1150--1650 {\AA} region. Bands of the Fourth Positive $(A1\Pi -X1\Sigma +)$ system involving $v\prime \prime =0$ and $v\prime =0-18$ have been analyzed. A discussion of the numerous perturbations in the $A 1\Pi$ state will be given. The potential curve and Franck-Condon factors have been recalculated from these data.