Named in honour of John Stanley Plaskett (b. 1865 in Hickson, Ontario, d. 1941), director of the Dominion Astrophysical Observatory in Victoria from its founding in 1917 to 1935; and of his son, Harry Hemley Plaskett (b. 1893, d. 1980), Savilian professor of astronomy at the University of Oxford and director of the Oxford Observatory from 1932 to 1960. Known for his work on the radial velocities of O- and B-type stars that provided observational confirmation of the theory of galactic rotation, J. S. Plaskett was also particularly associated with the massive Plaskett's star. The younger Plaskett made far-reaching contributions to stellar spectroscopy and spectrophotometry and to solar physics; as president of the Royal Astronomical Society just after World War II he was instrumental in bringing into being the 2.5-m telescope, completed in 1967 and initially installed at the Royal Greenwich Observatory at Herstmonceux. Both father and son were awarded the gold medal of the Royal Astronomical Society.
Reference: MPC 9081