Allan Sandage

Allan Sandage
Born	June 18 1926 Iowa City, Iowa
Nationality	American
Alma mater	California Institute of Technology University of Illinois
Scientific career
Fields	astronomy
Doctoral advisor	Edwin Hubble

Allan Rex Sandage (born June 18 1926 in Iowa City, Iowa) is an American astronomer.

Asteroids discovered: 1

(96155) 1973 HA

27 April 1973

Career

Allan R. Sandage is a notable scientist, whose major work was conducted during the 1960s. Sandage graduated from the University of Illinois in 1948. By 1953 he earned his Ph.D. from the California Institute of Technology. Sandage was a student of the famed cosmologist Edwin Hubble, and effectively continued Hubble's research program from the first part of the 20th century into the second half. Throughout the 1950s and well into the 1970s Sandage was regarded as the pre-eminent observational cosmologist. Sandage has made seminal contributions to all aspects of the cosmological distance scale from local calibrators within the galaxy to cosmologically distant galaxies.

Sandage began working at the Palomar Observatory. In 1958 he published the first good estimate for the Hubble parameter, namely 75 km/s/Mpc, which is quite close to today's accepted value. Later he became the chief advocate of an even lower value, around 50, corresponding to a Hubble age of around 20 billion years.

He performed spectral studies of globular clusters, and deduced that they had an age of at least 25 billion years. This led him to speculate that the universe did not merely expand, but actually expanded and contracted with a period of 80 billion years. The current cosmological estimates of the age of the universe, in contrast, are typically of the order of 14 billion years.

He is noted for the discovery in the M-82 galaxy of jets erupting from the core. These must have been caused by massive explosions in the core, and the evidence indicated the eruptions had been occurring for at least 1.5 million years.

Honors

Awards

• Helen B. Warner Prize for Astronomy (1957)
• Eddington Medal (1963)
• Gold Medal of the Royal Astronomical Society (1967)
• National Medal of Science (1970)
• Henry Norris Russell Lectureship (1972)
• Bruce Medal (1975)
• Crafoord Prize (1991)

Named after him

• Asteroid 9963 Sandage

Further reading

• Alan P. Lightman and Roberta Brawer, Origins: the lives and worlds of modern cosmologists, Harvard University Press, 1990. Interviews with modern cosmologists, including Sandage.

• Timothy Ferris, The Red Limit: The Search for the Edge of the Universe, Harper Perennial, 2002. Non-technical description of research, primarily up to about 1980, on cosmology; Sandage was a key figure, and features accordingly.

• Dennis Overbye, Lonely Hearts of the Cosmos: the story of the scientific quest for the secret of the Universe, HarperCollins 1991, Back Bay (with new afterword), 1999. Very well-written historical account of modern cosmology told through the careers of the scientists involved, in which Sandage is the central character. Complementary to Origins.

External links

• Bruce Medalist page on Sandage