Josef Hopmann (22 December 1890 – 11 October 1975) was a German

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...

. He was born in

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

and received his education at universities in Bonn and Berlin, then became an assistant at

Bonn Observatory The federal city of Bonn ( lat, Bonna) is a city on the banks of the Rhine in the German state of North Rhine-Westphalia, with a population of over 300,000. About south-southeast of Cologne, Bonn is in the southernmost part of the Rhine-Ruhr r ...

in 1914. In 1930 he became a full professor and was appointed director of the Leipzig Observatory and

Vienna Observatory The Vienna Observatory (german: Universitätssternwarte Wien) is an astronomical observatory in Vienna, Austria. It is part of the University of Vienna. The first observatory was built in 1753–1754 on the roof of one of the university buildings ...

. Between 1918 and 1974 he published nearly 100 scientific papers. In 1931–32, he and Heribert Schneller discovered that Zeta Aurigae is an

eclipsing binary A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in wh ...

. The minor planet 1985 Hopmann is named after him, as is the crater Hopmann on the

far side of the Moon The far side of the Moon is the lunar hemisphere that always faces away from Earth, opposite to the Near side of the Moon, near side, because of synchronous rotation in the Moon's orbit. Compared to the near side, the far side's terrain is ru ...

References

* * * {{DEFAULTSORT:Hopmann, Josef 1890 births 1975 deaths University of Bonn alumni 20th-century German astronomers