This paper reports a high-resolution experimental study of the and electronic states of the dimer. In the experiment, rovibrational levels of the two electronic states were probed using the perturbation facilitated optical-optical double resonance technique by exciting molecules from thermally populated levels of the ground state through intermediate levels of the mixed electronic states. The resonances of the probe laser were observed by detecting the laser induced fluorescence from the target states to the triplet ground state. In addition, to confirm the triplet character as well as the vibrational quantum number assignment of the states, for selected resonances the fluorescence to the state was resolved and bound-free spectra were recorded. From the observed term values for each state potential-energy curves were constructed using the Rydberg-Klein-Rees method.