Clabon Walter (Cla) Allen FRAS, (28 December 1904 – 11 December 1987) was an Australian

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 ...

, director of the

University of London Observatory UCL Observatory (called the University of London Observatory until 2015) at Mill Hill in London is an astronomical teaching observatory. It is part of the Department of Physics and Astronomy at University College London. History The Observator ...

and author of ''Astrophysical Quantities''. Allen was born at Subiaco, Perth the third child of James Bernard Allen (died 1912), a

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

n-born lecturer in physics at

Perth Technical School Central Institute of Technology was a Technical and Further Education (TAFE) institution based in Perth, Western Australia until 2016, at which point it became a part of North Metropolitan TAFE. It was the equal oldest post-secondary educationa ...

, and his wife Alice Hooper, ''née'' Aitken, a

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

-born trained nurse. Cla (as he was known) was educated at the High School,

Perth, Western Australia Perth () is the list of Australian capital cities, capital city of Western Australia. It is the list of cities in Australia by population, fourth-most-populous city in Australia, with a population of over 2.3 million within Greater Perth . The ...

and the

University of Western Australia University of Western Australia (UWA) is a public research university in the Australian state of Western Australia. The university's main campus is in Crawley, Western Australia, Crawley, a suburb in the City of Perth local government area. UW ...

(B.Sc., 1926; M.Sc., 1929; D.Sc., 1936). Allen was appointed to a research fellowship at the newly established Commonwealth Solar Observatory in 1926 at

Mount Stromlo Mount Stromlo (formerly Mount Strom ) is a mountain with an elevation of that is situated in the Australian Capital Territory, Australia. The mountain is most notable as the location of the Mount Stromlo Observatory. The mountain forms par ...

Australian Capital Territory The Australian Capital Territory (ACT), known as the Federal Capital Territory until 1938, is an internal States and territories of Australia, territory of Australia. Canberra, the capital city of Australia, is situated within the territory, an ...

, becoming an assistant there in 1928. Allen observed the 1 October 1940 solar eclipse in

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 ...

and obtained important results on the

solar corona In astronomy, a corona (: coronas or coronae) is the outermost layer of a star's Stellar atmosphere, atmosphere. It is a hot but relatively luminosity, dim region of Plasma (physics), plasma populated by intermittent coronal structures such as so ...

, including measurements of its electron density which were to prove invaluable to radio astronomers. Allen accepted an invitation by Sir Harrie Massey in 1951 to become Perren professor of astronomy at

University College, London University College London (Trade name, branded as UCL) is a Public university, public research university in London, England. It is a Member institutions of the University of London, member institution of the Federal university, federal Uni ...

, and director of the

Mill Hill Mill Hill is a suburb in the London Borough of Barnet, England. It is situated around northwest of Charing Cross, close to the Hertfordshire border. It was in the Historic counties of England, historic county of Middlesex until 1965, when it b ...

. Within a few years Allen had built up his observatory into one of the best astronomical departments in England. He published the first edition of ''Astrophysical Quantities'' in 1955, a compilation of numerical data of astrophysical interest. Universally known as "AQ", it is the most quoted book on the subject.

References

External links

Allen, Clabon Walter (1904–1987)
at Encyclopedia of Australian Science
Interview with Clabon Allen, Professor of Astronomy / Interviewer: Amy MacGrath. (sound recording)
at Trove, National Library of Australia {{DEFAULTSORT:Allen, Clabon Walter 1904 births 1987 deaths 20th-century Australian astronomers Fellows of the Royal Astronomical Society Academics of University College London University of Western Australia alumni