Walter Robert Wilhelm Grotrian was a German astronomer and astrophysicist.
Education
Grotrian studied the emission line from the solar corona in the green region of the spectrum. This emission line could not be attributed to any known chemical element and was thought to be a new element (which scientists named "coronium").
Career
Grotrian and Bengt Edlén from Sweden demonstrated that the two observed emission lines arise from iron atoms that have lost about half their 26 electrons. The impact crater Grotrian on the Moon
The Grotrian diagram in atomic spectroscopy showing the allowed transitions between atomic energy levels
Character in "Time Keeps on Slippin"" episode of Futurama.
Membership
German Academy of Sciences at Berlin.