_Walraven.png) Modelled shape ofWalraven from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | H. van Gent |
| Discovery site | Johannesburg Obs. (Leiden Southern Station) |
| Discovery date | 8 August 1931 |
| Designations | |
| (1946) Walraven | |
Named after | Theodore Walraven (astronomer)[2] |
| 1931 PH · 1952 PB 1959 RE1 · 1966 TC 1972 JE1 | |
| main-belt · (inner)[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 85.73 yr (31,314 days) |
| Aphelion | 2.8329AU |
| Perihelion | 1.7564 AU |
| 2.2947 AU | |
| Eccentricity | 0.2346 |
| 3.48yr (1,270 days) | |
| 242.32° | |
| 0° 17m 0.6s / day | |
| Inclination | 8.1606° |
| 17.269° | |
| 340.01° | |
| Physical characteristics | |
| 9.205±0.109 km[4][5] 11.83 km(calculated)[3] | |
| 10.21±0.01 h[6] 10.2101±0.0005 h[7] 10.22±0.02 h[8] 10.223h[9] | |
| 0.20(assumed)[3] 0.362±0.067[4][5] | |
| S[3] | |
| 11.9[4] · 12.0[1][3] | |
1946 Walraven (prov. designation:1931 PH) is a stonyasteroid from the inner regions of theasteroid belt, approximately 10 kilometers in diameter. It was discovered on 8 August 1931, by Dutch astronomerHendrik van Gent atLeiden Southern Station, annex to theJohannesburg Observatory in South Africa, and named after astronomerTheodore Walraven.[2][10]
Walraven is a stonyS-type asteroid that orbits the Sun in theinner main-belt at a distance of 1.8–2.8 AU once every 3 years and 6 months (1,270 days). Its orbit has aneccentricity of 0.23 and aninclination of 8° with respect to theecliptic.[1] The body'sobservation arc begins one day prior to its official discovery observation.[10]
Thisminor planet was named in honor of astronomer and pioneer in optical instrumentation and precision photometry, Theodore Fjeda Walraven (1916–2008),[11] who was a professor at theLeiden University and for many years resident astronomer at the former Leiden Southern Station near Hartbeespoortdam, South Africa.
Walraven constructed special photometers for the telescopes at the station, including the 5-color photometer for which he developed theWalraven photometric system.[2] The approved naming citation was published by theMinor Planet Center on 2 April 1988 (M.P.C. 12968).[12]
Four rotationallightcurves ofWalraven were obtained from photometric observation, giving arotation period between 10.210 and 10.223 hours with a brightness variation of 0.60 to 0.90magnitude (U=2+/n.a./2/2).[6][7][8][9]
According to the survey carried out by NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Walraven measures 9.2 kilometers in diameter and its surface has analbedo of 0.362,[4][5] while theCollaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20, and calculates a diameter of 11.8 kilometers with anabsolute magnitude of 12.0.[3]
