Johannes Fabricius

Johann(es) Fabricius (8 January 1587 – 19 March 1616), eldest son of David Fabricius (1564-1617), was a Frisian/German astronomer and a discoveror of sunspots, independently of Galileo Galilei.

Biography

Johannes was born in in Resterhafe (Friesland). He returned from university in the Netherlands with telescopes that they turned on the Sun. Despite the difficulties of observing the sun directly, they noted the existence of sunspots, the first confirmed instance of their observation (though unclear statements in East Asian annals suggest that Chinese astronomers may have discovered them with the naked eye previously, and Fabricius may have noticed them himself without a telescope a few years before). The pair soon invented camera obscura telescopy so as to save their eyes and get a better view of the solar disk, and observed that the spots moved. They would appear on the eastern edge of the disk, steadily move to the western edge, disappear, then reappear at the east again after the passage of the same amount of time that it had taken for it to cross the disk in the first place.

Copies of a map he made of Frisia in 1589 are also still extant. He is also name-checked in Jules Verne's "From the Earth to the Moon" as someone who claimed to have seen lunar inhabitants through his telescope, though that particular fact is merely part of Verne's fiction. The large (90 kilometer) Fabricius crater on the Moon's southern hemisphere is named after David Fabricius.

He died in Marienhafe.

Legacy

In 1895 a monument was erected to his memory in the churchyard at Osteel where he was pastor from 1603 until 1617.

Work

*Joh. Fabricii Phrysii "De Maculis in Sole observatis, et apparente earum cum Sole conversione, Narratio etc. Witebergae Anno M.DC.XI."

Literature

*Gerhard Berthold: "Der Magister Johann Fabricius und die Sonnenflecken, nebst einem Excurs über David Fabricius", Leipzig 1894
*L. Häpke: "Fabricius und die Entdeckung der Sonnenflecken", in: Abhandlungen des naturwissenschaftlichen Vereins zu Bremen 10, 1888, S. 249-272
*Bunte: "Über Johannes Fabricus, den Entdecker der Sonnenflecken", in: Jahrbuch der Ges. für bildende Kunst und vaterländ. Altertümer zu Emden 9, H. 1, 1890, S. 59-77
*Diedrich Wattenberg: "David Fabricius. Der Astronom Ostfrieslands", Berlin 1964.
*Fritz Krafft: in Walther Killys "Literaturlexikon: Autoren und Werke deutscher Sprache." (15 Bände) Gütersloh; München: Bertelsmann-Lexikon-Verl. 1988-1991 (CD-ROM Berlin 1998 ISBN 3-932544-13-7) Bd. 3 S.
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