Thorium in the spectrum of HR465

THE peculiar A star HR465 is a spectrum variable 1 . Considerable attention 2,3 has been given to the spectra of this star obtained by W. P. Bidelman during 1960–61, when the lines of the rare earth elements attained their maximum intensity; Bidelman has kindly placed this material at our disposal. Among the remarkable aspects of the HR465 spectrum is the fact that it is the only star for which a firm statistical basis exists for the identification of uranium 4 .