Discovered by H. van Gent MPC designation 1946 Walraven Discovered 8 August 1931 Inclination 8.1631° Asteroid group Asteroid belt | Discovery date 8 August 1931 Minor planet category main-belt · (inner) Aphelion 2.83 m Orbits Sun Discovery site Union Observatory | |
Named after Theodore Walraven(astronomer) Alternative names 1931 PH · 1952 PB1959 RE1 · 1966 TC1972 JE1 | ||
1946 Walraven, provisional designation 1931 PH, is a stony asteroid from the inner regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 8 August 1931, by Dutch astronomer Hendrik van Gent at Leiden Southern Station, annex to the Johannesburg Observatory in South Africa.
The S-type asteroid orbits the Sun at a distance of 1.8–2.8 AU once every 3 years and 6 months (1,270 days). Its orbit has an eccentricity of 0.23 and an inclination of 8° with respect to the ecliptic. The body's observation arc begins one day prior to its official discovery observation.
Four rotational light-curves of Walraven were obtained from photometric observation, giving a rotation period between 10.210 and 10.223 hours with a brightness variation of 0.60 to 0.90 magnitude (U=2+/n.a./2/2).
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Walraven measures 9.2 kilometers in diameter and its surface has an albedo of 0.362, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20, and calculates a diameter of 11.8 kilometers based on an absolute magnitude of 12.0.
The asteroid was named in honor of astronomer and pioneer in optical instrumentation and precision photometry, Theodore Walraven (1916–2008), who was a professor at the Leiden University and for many years resident astronomer at the former Leiden Southern Station near Hartbeespoortdam, South Africa. He constructed special photometers for the telescopes at the station, including the 5-color photometer for which he developed the Walraven photometric system. Naming citation was published on 2 April 1988 (M.P.C. 12968).