Jean Bosler (24 March 1878 in Angers – 25 September 1973 in Marseille) was a French astronomer[1] and author of several books.

[2] In 1912, he showed in his doctoral dissertation (supervised by Henri Poincaré) that the Sun’s magnetic field, by means of the intermediary of the solar wind, explains many aspects of cometary tails, the aurora borealis and aurora australis, solar storms and telluric currents.

During a solar eclipse in 1914, Bosler observed in the corona a spectral band “nouvelle, intense et unique” which he suggested was spectral evidence for coronium; however, in the 1930s subsequent research showed that the cause was a highly ionized form of iron.

In 1916, he published an analysis of the circular form of lunar craters as caused by the impact of meteors.

Bosler made important contributions to the theory of the evolution of stars and published the first textbook in French that dealt with the then recent discoveries of Hubble and the work on optical phenomena of such physicists as Michelson, Fabry and Perot.