Willem Hendrik van den Bos

Biography

Van den Bos was born in Rotterdam in 1896. He studied astronomy at Leiden University and worked at the Leiden Observatory. 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 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.

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 until 1966 when he was forced to stop owing to severe illness.

During the 31 years of his career he discovered 2895 new double stars and made 71929 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, published in 1963, with the collaboration of H.M. Jeffries and F.M. Greeby of the Lick Observatory, California. The catalogue later became the Washington Double Star Catalog.

In 1926 Van den Bos, in co-operation with Robert T.A. Innes, developed a new method of computing the orbits of double stars, based on the so-called Thiele−Innes elements, and used it to determine the orbits of more than 100 binary stars. Their method became the accepted standard procedure.