Joan George Erardus Gijsbertus Voûte (7 June 1879 – 20 August 1963) was a Dutch

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

. He was born in Madioen,

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

to a

Huguenot The Huguenots ( , ; ) are a Religious denomination, religious group of French people, French Protestants who held to the Reformed (Calvinist) tradition of Protestantism. The term, which may be derived from the name of a Swiss political leader, ...

family. He studied

civil engineering Civil engineering is a regulation and licensure in engineering, professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads ...

at Delft, but while a student he developed an interest in astronomy—studying

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes systematically with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are ...

s. After graduating he joined the staff of the

Leiden Observatory Leiden Observatory () is an astronomical institute of Leiden University, in the Netherlands. Established in 1633 to house the quadrant of Willebrord Snellius, it is the oldest operating university observatory in the world, with the only older sti ...

, where he worked on

binary star A binary star or binary star system 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 as separate stars us ...

s. In 1913 he gained a post at the

Cape Observatory The South African Astronomical Observatory (SAAO) is the national centre for optical and infrared astronomy in South Africa. It was established in 1972. The observatory is run by the National Research Foundation of South Africa. The facility's f ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

, where he worked on double stars and

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different sightline, lines of sight and is measured by the angle or half-angle of inclination between those two lines. Due to perspective (graphica ...

measurements. He became a Fellow of the

Royal Astronomical Society The Royal Astronomical Society (RAS) is a learned society and charitable organisation, charity that encourages and promotes the study of astronomy, planetary science, solar-system science, geophysics and closely related branches of science. Its ...

in 1917 (and was re-elected in 1953 after his membership lapsed during the war). His preliminary account of the parallax of

Proxima Centauri Proxima Centauri is the nearest star to Earth after the Sun, located 4.25 light-years away in the southern constellation of Centaurus. This object was discovered in 1915 by Robert T. A. Innes, Robert Innes. It is a small, low-mass st ...

was published in 1917, demonstrating that Proxima was the same distance from the Sun as the

Alpha Centauri Alpha Centauri (, α Cen, or Alpha Cen) is a star system in the southern constellation of Centaurus (constellation), Centaurus. It consists of three stars: Rigil Kentaurus (), Toliman (), and Proxima Centauri (). Proxima Centauri ...

system. He returned to Java in 1919, where he served as an assistant at the

Weltevreden Weltevreden may refer to: *Sawah Besar, a subdistrict of Central Jakarta, Indonesia, the core of the larger colonial district of Weltevreden in Batavia, Java *Weltevreden, Java Sawah Besar is a Districts of Indonesia, district (''kecamatan'') of ...

meteorological and magnetic observatory. There he was able to gain the interest of wealthy friends for the construction of an observatory. Voûte became the Director, and he selected the 1,300 m altitude

Lembang Lembang is a town and administrative village of West Bandung Regency in the province of Jawa Barat, West Java in Java (island), Java, Indonesia. The town has about 17,000 inhabitants (at census 2010). The population of the Lembang District was 17 ...

for the site. The main instrument was a 60 cm Zeiss double

refractor A refracting telescope (also called a refractor) is a type of optical telescope that uses a lens as its objective to form an image (also referred to a dioptric telescope). The refracting telescope design was originally used in spyglasses and ...

. The work of the observatory focused on double stars, parallax measurements, photometry of variable stars and

clusters may refer to: Science and technology Astronomy * Cluster (spacecraft), constellation of four European Space Agency spacecraft * Cluster II (spacecraft), a European Space Agency mission to study the magnetosphere * Asteroid cluster, a small ...

, and so forth. The results were published in the ''Lembang Observatory Annals''. Following the

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

ese occupation of Java, Voûte was imprisoned. As a result of his captivity he suffered from poor health, so after the war he moved to

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. Later he settled in

The Hague The Hague ( ) is the capital city of the South Holland province of the Netherlands. With a population of over half a million, it is the third-largest city in the Netherlands. Situated on the west coast facing the North Sea, The Hague is the c ...

, the Netherlands, where he died in 1963. Voûte became a corresponding member of the

Royal Netherlands Academy of Arts and Sciences The Royal Netherlands Academy of Arts and Sciences (, KNAW) is an organization dedicated to the advancement of science and literature in the Netherlands. The academy is housed in the Trippenhuis in Amsterdam. In addition to various advisory a ...

in 1922, he resigned in 1951.

References

* * {{DEFAULTSORT:Voute, Joan George 1879 births 1963 deaths People from Madiun Delft University of Technology alumni 20th-century Dutch astronomers Dutch people of French descent Fellows of the Royal Astronomical Society Members of the Royal Netherlands Academy of Arts and Sciences Dutch people of the Dutch East Indies