Spectral energy distributions of T Tauri stars.

The spectral energy distributions of T Tauri stars and related objects have been measured with a photoelectric spectrum scanner from 0.33 to 1.11 Reddening corrections derived from the spectral types show an increase towards earlier type presumably due to the presence of circumstellar material. This in turn provides qualitative support for Larson's evolutionary scheme for stars of low mass ( 2 M ) with an age of 8 x 10 years for the Taurus association. The corrected energy distributions indicate clearly the peculiar nature of the ultraviolet and blue continuous emission from T Tauri stars. Emission-line fluxes are also measured for the brighter hydrogen, calcium and helium lines. A strong correlation is found between the ultraviolet flux and the Ca II K emission and indicates a chromospheric origin for the various emission phenomena. Key words: T Tauri stars - spectral energy distribution - circumstellar reddening