Allan R. Sandage, 18 June 1926 - 13 November 2010
  Allan Sandage was an observational astronomer who was happiest at a
telescope. On Hubble's sudden death Allan Sandage inherited the programmes
using the world's largest optical telescope at Palomar to determine the
distances and number counts of galaxies. Over many years he greatly revised the
distance scale and, on re-working Hubble's analysis, discovered the error that
had led Hubble to doubt the interpretation of the galaxies' redshifts as an
expansion of the universe. Sandage showed that there was a consistent age of
Creation for the stars, the elements, and the Cosmos. Through work with Baade
and Schwarzschild he discovered the key to the interpretation of the
colour-magnitude diagrams of star clusters in terms of stellar evolution. With
others he founded Galactic Archaeology, interpreting the motions and elemental
abundances of the oldest stars in terms of a model for the Galaxy's formation.
He published several fine atlasses and catalogues of galaxies and a definitive
history of the Mount Wilson Observatory.
