The S-0 and S-1 states' vibronic features of two low-energy conformers of octahydroanthracene have been investigated by laser induced fluorescence excitation, dispersed emission and UV-UV hole burning spectroscopy in a cold seeded jet. UV-UV hole burning spectra have been used to distinguish the two conformers and their S-1 state vibrational modes. In addition, semi-empirical and ab initio calculations have been performed to correlate the calculated S-0 frequencies of vibrational modes with the experimental results. It is found that the observed spectra correspond well with sym-twist (a) (C-2h) and antisym-twist (b) (D-2) forms. (C) 2002 Elsevier Science B.V. All rights reserved.