June 29th 1818 birth of Angelo Seechi pioneer of stellar spectroscopy
Between 1864 and 1868 the Italian Jesuit Angelo Seechi made the first really good spectroscopic survey of the brightest stars. He divided the stars into four types.
The four types were Type I White Stars, Type II Yellow Stars, Type III Orange Stars, Type IV Red Stars. He also undertook major research into the Sun. He died in 1878.