April 10: Sidney Dean Townley

Sidney Dean Townley 

April 10, 1867 – March 18, 1946

Sidney Dean Townley was an American astronomer and geodeticist. During his second year at the university he took a course in astronomy. He was also given a room at the Washburn Observatory and worked nights as an assistant. These would serve to shape his interest in astronomy. 

In his second year as a graduate student he was offered a Hearst fellowship at the Lick Observatory, which he accepted, arriving in 1892. In 1893, however, the fellowship funds were re-committed to an eclipse expedition to Chile, so he had to depart. 

He became an instructor of astronomy, first at the University of Michigan, followed by the University of California. From 1893 until 1898 he worked at the Detroit Observatory, where he studied variable stars and comets. 

By 1897 he gained his Sc.D. from the University of Michigan with a thesis on the "Orbit of Psyche". In 1898 he spent a year on leave to travel through Germany, visiting major observatories in Berlin, Leipzig, and Munich. After his return he began teaching at the University of California, Berkeley, and was appointed director of the International Latitude Station at Ukiah, California. While there he developed an interest in geodesy, particularly seismology.

Townley was a member of the Astronomical Society of the Pacific and served as its president in 1916, and also spent time as director and on the publication committee. He also joined the Seismological Society, and served at various times as president, secretary-treasurer, and editor of the society journal. 

In 1911 he became an assistant professor at Stanford University. In a short time he became full professor, and would remain in that position until his retirement in 1932, thereafter becoming professor emeritus. 

During his career he published roughly 100 academic papers, and edited the contributions of many others. He was widely recognized for his editorial skills. 

The crater Townley on the Moon is named in his honor.