Johann Fabricius (astronomer)

Johann Fabricius (also Johannes Fabricius, * 8. January 1587 in Osteel (district Aurich); † 1615 in Marienhafe) were a German physician and astronomer. He discovered independently of Galileo Galilei the sunspots.

Johann Fabricius was the oldest son of eight children of the minister and astronomer David Fabricius, which operated extensive astronomical and meteorological research and in exchanges of letters with Tycho Brahe, Johannes Kepler and Simon Marius stood.

Over Johann Fabricius´ childhood and youth is little well-known. When twelve-year-old boy got over Johann an illness at the plague, which afflicted Northern Germany 1598 as epidemic disease. Later it, like its father, already visited the latin school in Braunschweig. From there out it sent repeatedly weather forecasts, which these to its “Calendarium” took up to its father.

After conclusion of the school it took up a study at the university of Helmstedt , at which its father had already studied in May 1605. Apart from the usual basic studies at the philosophical faculty busy it itself with the medicine. However it already changed 1606 to the university of joke mountain, where it remained three years and apart from grammar, dialectic and studied Rhetorik also geometry , astronomy , chronology and physics. From joke mountain it wrote a letter at Johannes Kepler to 1608. Apart from the astronomy busy it itself, how its father, with which Astrologie was and convinced of the fact that she supplies safe realizations. Beyond that it believed a method of the weather forecast to have found. 1609 went to Fabricius to suffering, in order to study at the there University of medicine. In the summer 1611 it decreased/went back after joke mountain and acquired in September the title of a Magisters of philosophy. Over its further life nearly nothing is well-known. Obviously it studied first far medicine. It undertook several journeys, whereby it visited also Johannes Kepler.

During its time in suffering Fabricius acquired a telescope, which he brought also in the paternal house in Osteel. He observed among other things the sun, what was not harmless, since he did not have aids, in order to weaken the bright light. It shifted only the observation time in the tomorrow and evening hours, in which the sunlight was less sharp. To 27. He noticed February 1611 for the first time dark marks on the sun. Since it was uncertain first whether it concerned atmospheric features or an optical deception, he repeated his observations, whereby he consulted his father. Since their eyes were pulled in, they used a ungefährlichere observation method later: By means of a Lochblende they steered the sunlight into a darkened room and regarded the sun disk on a white piece paper (the principle of the Camera Obscura). The existence marks could be free of doubts proven. Their daily movement on the sun disk was attributed applicable to a self-rotation of the sun. In the June of the same yearly Johann Fabricius in joke mountain published a 22seitige writing (De Maculis in brine observatis et apparente earum cum brine conversione narratio), where it describes all details of the discovery and to its father a being entitled portion awards.

The discovery stood contrary to the classical opinion of the Aristoteles, after which the sun was perfect, and which Lehrmeinung of the church, according to which the sun unbefleckt as it were „“, as the virgin should be Maria. The Italian had Galilei, which was Englishman Thomas Harriot and the German Christoph Scheiner already in the year 1610 marks on the sun perception, Fabricius however first, which described the discovery in a scientific paper. However Galilei and Scheiner changed its work into the future with silence. As discoverers of the sunspots Fabricius indicated of Simon Marius in the Mundus Jovialis (1614) and of Kepler in the Ephemerides Novae (1618). Fabricius´ writing turned out during the next hundred years into oblivion, was then again discovered and in the year 1723 again presented.

The exact day of death of Johann Fabricius is not well-known, is however between that 9. March 1616 and that 7. Are appropriate for May 1617. Johannes Kepler showed up regretting over the early death of the young man eager talented after its words „and, who lives on by its writing over the sunspots “.


  • Joh. Fabricii Phrysii De Maculis in brine observatis, et apparente earum cum brine conversione, Narratio etc. Witebergae anno M.DC.XI.


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