Pierre Jules César Janssen

Janssen, Pierre Jules César

 

Born Feb. 22, 1824, in Paris; died Dec. 23, 1907, in Meudon. French astronomer. Member of the Paris Academy of Sciences (1873) and of the Royal Society of London (1875). One of the founders of the spectral analysis of celestial bodies.

In 1868 and independently of J. N. Lockyer, Janssen invented the spectral method of observing solar prominences on the limb of the sun’s disk during periods when the sun was not in eclpse.

REFERENCE

Neuimin, G. N. “P. Zh. Zhansen.” Izvestiia Russkogo astronomicheskogo obshchestva, 1909, issue 14, no. 8, pp. 285–90.