Abstract
Ten bands of the B2 Sigma +-X2 Sigma + transition of AlO (blue-green system) have been photographed with high resolution and analysed for the rotational structure. From the rotational analysis of these bands, namely 2-0, 3-1, 4-2, 5-3, 6-4, 7-5, 4-1, 5-2, 6-3 and 7-4, rotational constants of the nu '=4, 5, 6 and 7 levels have been determined for the first time. No perturbations have been observed in any of the vibrational levels up to the rotational levels observed.