Edvard Hugo von Zeipel (8 February 1873 – 8 June 1959) was a

Swedish Swedish or ' may refer to: Anything from or related to Sweden, a country in Northern Europe. Or, specifically: * Swedish language, a North Germanic language spoken primarily in Sweden and Finland ** Swedish alphabet, the official alphabet used by ...

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, moons, comets and galaxies – in either ...

, with the specialist fields of study of

celestial mechanics Celestial mechanics is the branch of astronomy that deals with the motions of objects in outer space. Historically, celestial mechanics applies principles of physics (classical mechanics) to astronomical objects, such as stars and planets, to ...

astrophotography Astrophotography, also known as astronomical imaging, is the photography or imaging of astronomical objects, celestial events, or areas of the night sky. The first photograph of an astronomical object (the Moon) was taken in 1840, but it was no ...

, and

theoretical astrophysics Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline said, Astrophysics "seeks to ascertain the nature of the hea ...

. He worked at the

Stockholm Observatory The Stockholm Observatory ( sv, Stockholms observatorium, 050) is an astronomical observatory and institution in Stockholm, Sweden, founded in the 18th century and today part of Stockholm University. In 1931, the new Stockholm Observatory ( sv, ...

from 1897 to 1900, participated in scientific expeditions to Spitzbergen in 1898, 1901, and 1902, then worked at the

Pulkovo Observatory The Pulkovo Astronomical Observatory (russian: Пулковская астрономическая обсерватория, Pulkovskaya astronomicheskaya observatoriya), officially named the Central Astronomical Observatory of the Russian Academ ...

from 1901 to 1902, the Paris observatory from 1904 to 1906, and the

Uppsala Astronomical Observatory The Uppsala Astronomical Observatory (UAO), Astronomiska observatoriet i Uppsala) is the oldest astronomical observatory in Sweden. It was founded in 1741, though there was a professorial chair of astronomy at the University of Uppsala from 1593 ...

from 1911. He proved a key theorem about the

Painlevé conjecture In physics, the Painlevé conjecture is a theorem about singularities among the solutions to the ''n''-body problem: there are noncollision singularities for ''n'' ≥ 4. The theorem was proven for ''n'' ≥ 5 in 1988 b ...

. Von Zeipel specialized in 'celestial mechanics, especially distribution of stars and globular star clusters, asteroid motions, and problems of radiation equilibrium. " In 1930, von Zeipel was awarded the A. Cressy Morrison Prize from the

New York Academy of Sciences The New York Academy of Sciences (originally the Lyceum of Natural History) was founded in January 1817 as the Lyceum of Natural History. It is the fourth oldest scientific society in the United States. An independent, nonprofit organization wi ...

for his theory that "the stars like the Sun were recurrent novae."

Named after von Zeipel

*The crater Von Zeipel on the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

is named after him. * 8870 von Zeipel is an asteroid discovered on March 6, 1992. It is also named after him. *

Von Zeipel theorem In astrophysics, the von Zeipel theorem states that the radiative flux F in a uniformly rotating star is proportional to the local effective gravity g_\text. The theorem is named after Swedish astronomer Edvard Hugo von Zeipel. The theorem is: ...

, linking stellar radiative flux to local effective gravity.

References

External links

Hugo von Zeipel
in ''Nordisk familjebok, 33 (1922), col. 711. (in Swedish) 1873 births 1959 deaths People from Haninge Municipality 20th-century Swedish astronomers 19th-century Swedish astronomers Members of the Royal Society of Sciences in Uppsala {{Europe-astronomer-stub