Willem Hendrik van den Bos (25 September 1896 – 30 March 1974) was a Dutch

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 ...

who worked at the Union Observatory in South Africa and became its director in 1941. He discovered nearly new double stars, made more than astronomical measurements and compiled a catalogue of Southern hemisphere double stars. He computed the orbits of more than 100 double stars using a method he invented and which later became the accepted standard.

Biography

Van den Bos was born in

Rotterdam Rotterdam ( , , , lit. ''The Dam on the River Rotte'') is the second largest city and municipality in the Netherlands. It is in the province of South Holland, part of the North Sea mouth of the Rhine–Meuse–Scheldt delta, via the ''"Ne ...

in 1896. He studied

astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...

at Leiden University and worked at the

Leiden Observatory Leiden Observatory ( nl, Sterrewacht Leiden) is an astronomical institute of Leiden University, in the Netherlands. Established in 1633 to house the quadrant of Rudolph Snellius, it is the oldest operating university observatory in the world, wit ...

. In 1925 he completed his PhD in astronomy under the supervision of Willem de Sitter and was invited by R.T.A. Innes to join the Union Observatory in

Johannesburg Johannesburg ( , , ; Zulu and xh, eGoli ), colloquially known as Jozi, Joburg, or "The City of Gold", is the largest city in South Africa, classified as a megacity, and is one of the 100 largest urban areas in the world. According to Dem ...

for a three-year appointment as assistant to the director, H.E. Wood. Innes was eager to have an experienced observer of double-stars to share the workload on the newly erected

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observ ...

. Van den Bos extended his appointment at the Union Observatory indefinitely and in 1941 was appointed Director of the observatory. He retired from the observatory in 1956 but continued his observations both in South Africa and the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

until 1966 when he was forced to stop owing to severe illness. During the 31 years of his career he discovered new double stars and made astronomical measurements. He compiled a catalogue from previous observations of southern hemisphere double stars that was incorporated into the

Index Catalog of Visual Double Stars The Index Catalogue of Visual Double Stars, or IDS, is a catalog of double stars. It was published by Lick Observatory in 1963 and contains measurements for 64,250 objects, covering the entire sky. The database used to construct this catalog was ...

, published in 1963, with the collaboration of H.M. Jeffries and F.M. Greeby of the Lick Observatory,

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

. The catalogue later became the

Washington Double Star Catalog The Washington Double Star Catalog, or WDS, is a catalog of double stars, maintained at the United States Naval Observatory. The catalog contains positions, magnitudes, proper motions and spectral types and has entries for (as of June 2017) 141, ...

. Van den Bos developed his own method of measuring the orbits of double stars and used it to measure the orbits of more than 100 binary stars. His method became the accepted standard procedure.

Recognition, memberships, awards

* President of the Double Star Commission of the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

for 14 years. * Royal Danish Academy Gold Medal * Gill Medal from the Astronomical Society of Southern Africa * President of the Astronomical Society of Southern Africa in 1943 and 1955 *The 1969 Double-star Colloquium of the International Astronomical Union in

Nice Nice ( , ; Niçard dialect, Niçard: , classical norm, or , nonstandard, ; it, Nizza ; lij, Nissa; grc, Νίκαια; la, Nicaea) is the prefecture of the Alpes-Maritimes departments of France, department in France. The Nice urban unit, agg ...

was dedicated to Van den Bos. *The asteroid 1663 van den Bos is named after him, as is the lunar crater van den Bos.

References

External links

{{DEFAULTSORT:Van den Bos, Willem Hendrik 1896 births 1974 deaths 20th-century Dutch astronomers Dutch emigrants to South Africa Leiden University alumni Van den Bos, Willem Hendrik Scientists from Rotterdam