1935 ST1. Discovered 1935 Sept. 28 by H. van Gent at Johannesburg.
Named in memory of H. Zanstra (1894–1972), Dutch astronomer, director of the Astronomical Institute of the Municipal University in Amsterdam from 1946 to 1959. He is well known for his method for obtaining the surface temperatures of the central stars of planetary nebulae. (M 18135)
Obituary published in 18th Coll. Int. Astrophys. Liège 1972, P. 11–15 (1973).