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3 unusual facts about Pierre Janssen


Pierre Janssen

In 1875, Janssen was appointed director of the new astrophysical observatory established by the French government at Meudon, and set on foot there in 1876 the remarkable series of solar photographs collected in his great Atlas de photographies solaires (1904).

At the great Indian eclipse of 1868 that occurred in Guntur, Janssen also demonstrated the gaseous nature of the red prominences, and devised a method of observing them under ordinary daylight conditions.

While observing the solar eclipse of August 18, 1868, at Guntur, in Madras State now Andhra Pradesh, British India, he noticed bright lines in the spectrum of the chromosphere, showing that the chromosphere is gaseous.


Henri-Alexandre Deslandres

In 1868, Pierre Janssen's solar observations had led him to report to the Académie des Sciences that It is no longer geometry and mechanics which dominate in astronomy but physics and chemistry. Such advice was sternly rejected by director of the Paris Observatory Urbain Le Verrier and the French government awarded Janssen a grant to establish an astrophysical observatory at Meudon on the outskirts of Paris with Janssen as the sole astronomer.


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