January 24: Harold Delos Babcock

Harold Delos Babcock

January 24, 1882 – April 8, 1968

Harold Babcock was an American astronomer. Educated at the University of California, Berkeley, he was one of the first staff workers at the Mount Wilson Observatory. He worked there from 1909 until 1948 and he specialized in solar spectroscopy and mapped the distribution of magnetic fields over the Sun's surface. In the early years he made precision measurements of spectra in the laboratory and participated in solar research with George E. Hale. With his son he revealed the existence of strong magnetic fields in certain stars. Babcock’s precise laboratory studies of atomic spectra allowed others to identify the first “forbidden” lines in the laboratory and to discover the rare isotopes of oxygen. 

In 1953 he won the Bruce Medal. The Lunar crater Babcock is named in his honor, as is asteroid 3167 Babcock (jointly named after him and his son).