Pehr Wilhelm Wargentin
Pehr Wilhelm Wargentin (* September 11, 1717 (Jul. Cal ) in Sunne ( Jämtland ), Sweden, † December 13, 1783 in Stockholm) was a Swedish astronomer.
Life
Wargentin interested in early astronomy and watched in 12 years with his father, Wilhelm Wargentin a lunar eclipse. 1735, he began his studies at Uppsala University, where he graduated in 1743. 1737 encouraged him to Professor Anders Celsius, to observe the eclipse of the Galilean moons by Jupiter in more detail.
1741 put Wargentin after four years working his observation and calculation results to the recently completed observatory of Uppsala ago - Tabulae per calculandis eclipsibus satellitum Jovis in Acta Societatis Scientiarum Regiae Upsalaiensis per 1741 ( 1746 printing ). These observations were more accurate than those of his predecessors, and showed that the irregular moons circling Jupiter. The cause he suspected the mutual attraction between the moons. He also confirmed the finding of James Bradley, that the three Galilean moons Io, Europa and Ganymede are taking 19 hours and 41 minutes exactly the same position always after a period of 437 days. He suggested Joseph -Louis Lagrange in 1766 and Pierre- Simon Laplace in 1788 to draw up a declaration by the theory of gravitation by Isaac Newton. The coupling of the orbital periods of the three moons in the ratio 1: 2: 4 is now called Laplace - or orbital resonance.
After receiving his doctorate in 1743 and his professorship of Astronomy 1748 he became permanent secretary in 1749 the Royal Swedish Academy of Sciences in Stockholm. In 1753 he took over the line yet the Stockholm Observatory, procured equipment by Daniel Ekström, John Bird, John Dollond and moved into the building. As secretary he published the Proceedings of the Academy and built by many contacts with European scientists further. He participated in the determination of the distance between Earth and Sun by observing the Mars opposition in 1752 and the Transit of Venus in 1761 and 1769 in Stockholm.
In his Tabellenverket he collected from 1749 persons data from church records that had to be conducted from 1686. Thus Sweden was the first country in the world with a population statistic. Today, this work is done by the Central Statistical Office ( SCB).
In 1756 he married Christina Magdalena Raab. They had three daughters, and died in 1769 in a miscarriage.
In 1783 he became a foreign member of the Paris Academy of Sciences. The lunar crater Wargentin and high school in Östersund ( Wargentinsskolan ) were named after him.
In today's Observatory Museum in Stockholm his study is shown.