Photoionization bands of rubidium molecule

•All sapphire cell enabled absorption measurements in deep ultraviolet spectral region at high temperature and high density.•Unusual structured photoionization bands of rubidium dimer have been observed overlying smooth atomic photoionization.•Possible interpretation is connected to direct and indirect photoionization of the rubidium molecule.•The results point to the urgent need of appropriate quantum-mechanical calculations of the doubly excited potential curves which are subjected to autoionization.