S2A3 Biographical Database of Southern African Science

Voute, Mr Joan George Erardus Gijsbertus (astronomy)

Born: 7 June 1879, Madiun, Java, Indonesia.
Died: 20 August 1963, Den Haag, The Netherlands.

J.G.E.G. Voute, a Dutch astronomer, was educated in The Netherlands and qualified in civil engineering at the technical university in Delft. During his student years he started observing variable stars, in which he retained an interest during his entire career. After qualifying he decided to make astronomy his life's work and in 1908 joined the staff of Leiden Observatory, where he worked mainly on double stars. His first double star orbit was published in the Monthly Notices of the Royal Astronomical Society in 1908 and was the first of many papers in this field, in which he became a leading expert.

Voute was keen to do observations in the southern hemisphere, where observatories and astronomers were few and far between. In 1913, with the help of Professor J.C. Kapteyn*, he obtained an appointment as a volunteer assistant at the Royal Observatory, Cape of Good Hope, where he worked mainly on double stars and the determination of stellar parallaxes. His double star work, 'Measures of double stars made at the Royal Observatory at the Cape of Good Hope (September 1913 to November 1917)' was later published in the Annals of the Bosscha Observatory (1925). With R.T.A. Innes he published 'Some stars with sensible proper motion on an astrographic plate centred upon Omega Centaurus' (Circular of the Union Observatory, Johannesburg, No. 25, 1915). He used the astrographic telescope to obtain stellar parallaxes by photography, using Kapteyn's method, which involved two exposures of the same photographic plate taken six months apart and measuring the small difference in position of the two images of the parallax star against the distant stellar background. His results, published in the Monthly Notices in 1916, 1917 and 1919, came to be regarded as useful preliminary values rather than firm determinations. However, his parallax of Proxima Centauri, a star that had only recently been discovered by R.T.A. Innes*, proved to be accurate and showed it to be at about the same distance as Alpha Centauri. It was later shown to be the nearest star to the solar system.

In 1919 Voute returned to Java, where he wished to start astronomical work. For some time he was an assistant at the meteorological and magnetic observatory at Weltevreden. Meanwhile he and two wealthy friends, K.A.R. Bosscha and R.A. Kerkhoven, with other interested persons, founded the Nederlandsch-Indische Sterrekundige Vereeniging (Dutch East Indies Astronomical Society) in 1920, with the aim of establishing an astronomical observatory on the island. Voute chose a site at Lembang, near Bandung, at an altitude of 1300 meters. The Bosscha Observatory was established there and opened in 1923, with Voute as director. It was equipped with a Zeiss 600 mm double refractor, designed for double star observations and parallax work, and other instruments of high quality. Many prominent astronomers came to work with Voute for some time, participating in research on double stars, stellar parallax, variable stars, photometry of clusters and other fields. Most of the research he carried out at the observatory was published in the Annals of Bosscha Observatory, including measures of double stars (1926, 1932), a catalogue of radial velocities (1928), determinations of stellar parallaxes (1933), and observations of variable stars (1935).

During World War II (1939-1945) Java was occupied by the Japanese and Voute was imprisoned for some time, during which his health deteriorated seriously. After the war he went to Australia, where some of his observations were reported in the publications of the Riverview Observatory, New South Wales. He later settled in The Netherlands. His final paper on double stars appeared in 1956.

List of sources:

Churms, J. Stellar parallax work at the Cape. Monthly Notes of the Astronomical Society of Southern Africa (MNASSA), 1970, Vol. 29, pp. 102-109.

Glass, I.S. The discovery of the nearest star. African Skies, 2007, No. 11, pp. 39-40

Google Scholar. http://scholar.google.co.za

National Union Catalogue, pre-1956 imprints. London: Mansell, 1968-1980.

O'Connell, D.J.K. Obituary Notices: Joan George Erardus Gijsbertus Voute. Quarterly Journal of the Royal Astronomical Society, 1964, Vol. 5, pp. 296-297.

Compiled by: C. Plug