The distinguishing features of luminescence of aqueous thymine solutions at
room temperature (a broadening of luminescence spectra as compared with lo
w-temperature spectra and differences between excitation, and absorption sp
ectra) are discussed. It is shown that these features are due to bimolecula
r photochemical reactions that lead to the formation of photoproducts (at t
he first stages, photoadducts) with a comparatively high luminescence abili
ty.