Lowest singlet excited state and spectroscopy of α-carotene

► Emission and absorption spectra of α-carotene were measured in solvents with different polarizabilities. ► In highly-polarized solvents α-carotene emits weak fluorescence from S1 with the origin near 14 800 cm−1. ► The relative S1/S2 fluorescence intensity ratio tends to increase with increasing solvent.