William McCrea (astronomer)

Sir William Hunter McCrea FRS (13 December 1904, Dublin – 25 April 1999)^[1][2] was an English astronomer and mathematician.

Biography

His family moved to Kent in 1906 and then Derbyshire where he attended Chesterfield Grammar School. His father was a school master at Netherthorpe Grammar School in Staveley. He went to Trinity College, Cambridge in 1923 where he studied Mathematics, later gaining a PhD in 1929 under Ralph H. Fowler. He was later appointed a lecturer of Mathematics at the University of Edinburgh in 1929. He also served as reader and assistant professor at Imperial College London. In 1936 he became head of the mathematics department at the Queen's University of Belfast. After serving in the war, he joined the mathematics department at Royal Holloway College in 1944 (the McCrea Building on Royal Holloway's campus is named after him). In 1965, McCrea created the astronomy centre of the physics department at the University of Sussex.

Discoveries

In 1928, he studied Albrecht Unsöld's hypothesis, and discovered that three quarters of the Sun is made of hydrogen, and about one quarter is helium, with 1% being other elements. Previous to this many people thought the Sun consisted mostly of iron. After this, people realised most stars consist of hydrogen.

In 1964 he proposed mass transfer mechanism as an explanation of blue straggler stars.^[3]

Awards

McCrea was president of the Royal Astronomical Society from 1961–3 and president of Section A of the British Association for the Advancement of Science from 1965–6. He was knighted in 1985. He won the Gold Medal of the Royal Astronomical Society in 1976. McCrea died on 25 April 1999 in Lewes.

References