Low resolution VUV absorption spectrum of boron monoxide

The absorption spectrum of BO has been recorded between 2400 and 300 A on the SA61 beam line of SUPERACO in Orsay. A new electronic transition has been observed and vibrationally analysed. Nine Rydberg states have been observed and classified into Rydberg series giving two ionization limits at 12.849eV for the X 1Σ+ ionic state and at 13.117eV for the A 1II state of BO+. Two ionization limits have been observed at 754 and 374 A. The first of these corresponds to the B 1Σ+ state and the last one to the C 1Σ+ state of BO+. The new results are compared with the ab initio calculations of Karna and Grein concerning BO and BO+. The agreement is satisfactory.