ИСТИНА

Though lenticular galaxies are thought to be `red and dead', really they often possess extended gaseous disks where current star formation can be noticed. Extended star formation has been reported in S0 disks in particular by the ultraviolet space telescope GALEX; and by observing spectrally a sample of the nearby S0s with ultraviolet rings we have found warm-gas emission lines in the most spectra which excitation betrays the presence of massive young stars in the outer rings of these galaxies. However sometimes the star formation does not proceed despite the large amount of the cold gas, and in these cases the peculiar kinematics of the gaseous disks can be often noted. We discuss the possible origin of the extended gaseous disks in S0 galaxies and try to reveal necessary conditions to ignite star formation through their large-scale disks.