Photo ca. 1907, courtesy Lowell Observatory
Vesto Melvin Slipher
11 November 1875	1935 Bruce Medalist	8 November 1969

“V.M.” Slipher was born in Indiana and educated at Indiana University. His entire career was spent at the Lowell Observatory, where he started immediately after receiving his A.B. in 1901 and which he directed from 1916 to 1954. His visible and infrared spectroscopic studies of planets led to the determination of rotation periods and the identification of molecules in planetary atmospheres. He discovered reflection nebulae and proved the existence of interstellar dust and gas. Using exposure times as long as 80 hours, he was the first to measure the enormous radial velocities of spiral nebulae; these data were later used and extended by Edwin P. Hubble to begin modern observational cosmology. Slipher discovered and measured the rotations of the spirals. He also supervised the successful search for a ninth planet.

Presentation of Bruce medal
Einarsson, S., PASP 47, 5-10 (1935).

Other awards
French Academy of Sciences, Lalande Prize, 1919.
National Academy of Sciences, Henry Draper Medal, 1932.
Royal Astronomical Society, Gold medal, 1933, presented by F.J.M. Stratton, MNRAS 93, 476-77 (1933).

Biographical materials
Bitterman, Jay, Lake County Astronomical Society
Giclas, Henry L., Biographical Encyclopedia of Astronomers (Springer, NY, 2007), p. 1066.
Hart, Richard & Richard Berendzen, Dictionary of Scientific Biography 12, 454-56.
Hoyt, William Graves, Biographical Memoirs of the National Academy of Science 52,410-49 (1980).
Lowell Observatory.
Smith, Robert W., “Red Shifts and Gold Medals: 1901-1954,” in William Lowell Putnam and others, The Explorers of Mars Hill (Phoenix Publishing, West Kennebunk, Maine, 1994), pp. 43 - 65.

Obituaries
Hall, John S., Sky & Telescope 39, 2, 84-86 (1970).
Hall, John S., Year Book of the American Philosophical Society 1970, 161-66.
More obituaries

Portraits
AIP Center for History of Physics
Lowell Observatory (3 photos)

Named after him
Lunar crater Slipher
Martian crater Slipher
Minor Planet #1766 Slipher (with his brother, Lowell Observatory astronomer E.C. Slipher)

More references