Bertil Lindblad (

Örebro Örebro ( , ) is the List of urban areas in Sweden by population, sixth-largest city in Sweden, the seat of Örebro Municipality, and capital of the Örebro County. It is situated by the Närke Plain, near the lake Hjälmaren, a few kilometers in ...

, 26 November 1895 –

Saltsjöbaden Saltsjöbaden is a locality in Nacka Municipality, Stockholm County, Sweden with 9,491 inhabitants in 2010. It is on the Baltic Sea coast, deep in the Stockholm Archipelago. History Saltsjöbaden () was developed as a resort by Knut Agathon Wa ...

, outside

Stockholm Stockholm () is the Capital city, capital and List of urban areas in Sweden by population, largest city of Sweden as well as the List of urban areas in the Nordic countries, largest urban area in Scandinavia. Approximately 980,000 people liv ...

, 25 June 1965) was a Swedish

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 ...

. After finishing his secondary education at Örebro högre allmänna läroverk, Lindblad matriculated at

Uppsala University Uppsala University ( sv, Uppsala universitet) is a public university, public research university in Uppsala, Sweden. Founded in 1477, it is the List of universities in Sweden, oldest university in Sweden and the Nordic countries still in opera ...

in 1914. He received his ''filosofie magister'' degree in 1917, his ''filosofie licentiat'' degree in 1918 and completed his doctorate and became a docent at the university in 1920. From 1927 he was professor and astronomer of the

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences ( sv, Kungliga Vetenskapsakademien) is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special ...

and head of the Stockholm Observatory. In the latter capacity he was responsible for the observatory's move from the old building in the centre of Stockholm to a newly built facility in

Saltsjöbaden 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, ...

, which was opened in 1931. Lindblad studied the theory of the rotation of

galaxies A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...

. By making careful observations of the apparent motions of stars, he was able to study the rotation of the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...

. He deduced that the rate of rotation of the stars in the outer part of the galaxy, where the Sun is located, decreased with distance from the galactic core. This deduction was soon confirmed by

Jan Oort Jan Hendrik Oort ( or ; 28 April 1900 – 5 November 1992) was a Dutch astronomer who made significant contributions to the understanding of the Milky Way and who was a pioneer in the field of radio astronomy. His ''New York Times'' obituary ...

in 1927. A certain class of resonances in rotating

stellar Stellar means anything related to one or more stars (''stella''). The term may also refer to: Arts, entertainment, and media * ''Stellar'' (magazine), an Irish lifestyle and fashion magazine * Stellar Loussier, a character from ''Mobile Suit Gun ...

or gaseous disks are named

Lindblad resonances A Lindblad resonance, named for the Swedish galactic astronomer Bertil Lindblad, is an orbital resonance in which an object's epicyclic frequency (the rate at which one periapse follows another) is a simple multiple of some forcing frequency. Res ...

, after Bertil Lindblad. His son, Per-Olof Lindblad, also became an astronomer.

Honors

Awards * Janssen Medal from the

French Academy of Sciences The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV of France, Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific me ...

(1938) *

Prix Jules Janssen The Prix Jules Janssen is the highest award of the Société astronomique de France (SAF), the French astronomical society. This annual prize is given to a professional French astronomer or to an astronomer of another nationality in recognition ...

, the highest award of the

Société astronomique de France The Société astronomique de France (SAF; ), the French astronomical society, is a non-profit association in the public interest organized under French law (Association loi de 1901). Founded by astronomer Camille Flammarion in 1887, its purpose ...

, the French astronomical society (1949) * Gold Medal of the Royal Astronomical Society (1948) * Bruce Medal (1954) Named after him *

Lindblad (crater) Lindblad is an old lunar impact crater that is located on the far side of the Moon, just beyond the northwestern limb. This formation is located to the southeast of the crater Brianchon, and northeast of Cremona Cremona (, also ; ; lmo, la ...

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 ...

Asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

1448 Lindbladia Year 1448 ( MCDXLVIII) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar. Events January–December * January 6 – Christopher of Bavaria, King of Denmark, Norway and Sweden, dies with ...

External links

* http://www.phys-astro.sonoma.edu/brucemedalists/lindblad—1954 Bruce Medalist Profile (with portrait) * {{DEFAULTSORT:Lindblad, Bertil 1895 births 1965 deaths 20th-century Swedish astronomers Uppsala University alumni Recipients of the Gold Medal of the Royal Astronomical Society Foreign associates of the National Academy of Sciences Presidents of the International Astronomical Union