Medal commemorating Pierre Janssen and Norman Lockyer, French and English astronomers, 1868. Artist: Unknown
Medal commemorating Pierre Janssen and Joseph Norman Lockyer, French and English astronomers, 1868. In 1868, working independently of each other on spectroscopic studies of solar prominences, Pierre Jules Cesar Janssen (1824-1907) and Joseph Norman Lockyer (1836-1920) both observed a yellow line in the solar spectrum. Lockyer named it Helium from helios (sun). Reverse of a commemorative medal showing Phaeton driving his father Apollo's chariot near the sun.