Allan Sandage dies

Allan Sandage has died at the age 84. He worked with Edwin Hubble as an assistant at Mount Wilson Observatory.He is the root of scale of  determining the Hubble Constant, which describes the Universe’s expansion.

He graduated from  Illinois University in 1948 and then achieved a PhD  in 1953 under the tutelage of Walter Baade and parallel y  he was working as an assistant to Hubble at Mount Wilson. In 1950 he  had discovered that Hubble’s estimate of the distance to the Andromeda Galaxy, 700,000 light years, was half too small, based on the identification of Cepheid variables in Andromeda.

In 1958 he won the American Astronomical Society’s Warner Prize on his work on evolution of stars and then they allowed him to develop a method of calculating the ages of stars that have left the main sequence of the Hertzsprung–Russell diagram.
After that using the Hale telescope he had worked out the miscalculations  in Hubble's distance measurements.

Anyways Sandage Sir .... RIP in peace and thanks for your root work , and I repeat , root work :)