WRIGHT, WILLIAM HAMMOND

(b. San Francis–co, California, 4 November 1871; d. San Jose, California, 16 May 1959)

astronomy

Wright was a skillful designer of astronomical equipment, which he used to photograph the spectra of stars and nebulae. He was also the first to use six-color photography in studying the planet Mars.

Wright’s parents were Joanna Maynard shaw and Selden Stuart Wright. After attending public schools in San Francisco, Wright went to the University of California, where he received a B.S. in civil engineering in 1893. He remained in Berkeley for two years of graduate study, specializing in astronomy, and then transferred for a year to the University of Chicago, where George Ellery Hale taught him the latest techniques for photographing spectra.

In 1897 Wright returned to California, as an assistant astronomer at the Lick observatory, to help W. W. Campbell in his studies of solar motion. For this purpose Wright photographed the spectra of many stars, to get line-of-sight velocities. In 1903 he was sent to Santiago, Chile, with a 36 1/2–inch telescope, which he installed on Cerro San Cristobal and used to acquire similar data for stars in the Southern hemisphere. He was accompanied by his wife, Elna Warren Leib, whom he had married in 1901. Wright remained in charge of this Southern station of Lick until 1906.

Back in California, Wright was promoted to astronomer in 1908, a post he held until 1944. In 1935 he was also appointed director of the Lick observatory, succeeding R. G. Aitken.

Wright investigated nebulae, particularly those called planetaries, and the high temperature stars that they surround. His data later helped I. S. Bowen to unravel the “nebulium” mystery.

Wright also continued work on novae, begun earlier with Campbell. His photographs of the specturn of Nova Geminorum 1912, taken on every possible night during more than nineteen months, provided a wealth of details basic to the understanding of such complicated explosive evebts.

Begining in 1924, while Mars was well situated for observation, Wright used the Crossley 36–inch reflector at Lick to photograph this planet (and also Jupiter, Saturn, and Venus) on suitably sensitized emulsions exposed through a series of filters, in colors ranging from ultraviolet through the visible to the infrared. The enhanced contrast, particularly for Mars in the infraed , revealed, many unsuspected details.

Wright’s final project was a set of about 1,300 large-scale celestial photographs, to be repeated for comparison after several decades and thus provide information on motions within our galaxy. Interrupted by World War II, it was succeeded Wright as director of Lick.

The National Academy of Sciences elected Wright to membership in 1922, and awarded him its Draper Medal in 1928, the same year that he received the Janssen Medal of the Paris Academy of Sciences. He was elected a fellow of the Royal Astronomical Society (London) in 1927, and was awarded its Gold Medal in 1938. Wright’s two advanced degrees were both honorary: a D.Sc. from Northwestern University (1929) and an LL.D from the University of California (1944).

BIBLIOGRAPHY

I. Original Works. An early paper by Wright on in srtumentation “The Auxiliary Apparatus to the Mills Spectrogaphy for Photogrpahing the Comparison Spectrum” is in Astrophysical Journal21 (1900) 274–278, For a brief accounts of Wright’s work in Chile, see “On Some Results Obtained by the D. O. Mills Expedition ot the Southern Hemisphere” ibid; 20 (1904) 140–145. His ideas concerning the central star of planetary nebulae are described in “The Relation Between the Wolf Rayet Stars and the Planeatry Nebulae,” ibid; 40 (1914) 466–472. Wright photographs og Mars and other plantes are described and illustraed in his George Darwin Lecture “On photography of the Brighter Planets by Light of Different Colurs,” in Monthly Notices of the Royal Astronomical Society, 88 (1928) 079–718, with 34 figs on 3, plates.

“The Spectrum of Nova Geminorum (9121)” appears in Publicatiponss of the Lick Observatory14 (1940) 27–91.

II. Secondary Literature. Comtemporary appraisals of Wright’swork inculde the adress delived by H.Spencer Jones when awarding the gold Medal to Wrights in Monthly Noticed of the Royal Astronomical Soceity98 (1938)358–374. An obituary noitce by Paul W. Merli is in Published of the Astronomical Society of the Pacific71 (1995) 305–306 with a photography of Wright’s another by C. D. Shane can be fpound in American Philosophicals Soceity Yearbook for 1959 150–153.

Sally H. Dieke