_Luanda.png) Modelled shape ofLuanda from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | C. Jackson |
| Discovery site | Johannesburg |
| Discovery date | 29 July 1937 |
| Designations | |
| (1431) Luanda | |
Named after | Luanda[2] (Capital of Angola) |
| 1937 OB · 1949 KZ | |
| main-belt · (middle) Eunomia[3][4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 80.22 yr (29,300 days) |
| Aphelion | 3.0989AU |
| Perihelion | 2.1408 AU |
| 2.6199 AU | |
| Eccentricity | 0.1829 |
| 4.24yr (1,549 days) | |
| 293.57° | |
| 0° 13m 56.64s / day | |
| Inclination | 13.987° |
| 117.73° | |
| 224.19° | |
| Physical characteristics | |
| Dimensions | 13.608±1.966 km[5] 13.88 km(calculated)[3] |
| 4.141±0.004 h[6] 5.360±0.002h[7] | |
| 0.21(assumed)[3] 0.360±0.347[5] | |
| LS [8] · S(assumed)[3] | |
| 11.06[5] · 11.6[3] · 11.7[1] · 12.38±0.42[8] | |
1431 Luanda, provisional designation1937 OB, is a stony Eunomianasteroid from the central regions of theasteroid belt, approximately 14 kilometers in diameter. It was discovered on 29 July 1937, by South African astronomerCyril Jackson at theUnion Observatory in Johannesburg.[9] The asteroid was named after the city ofLuanda.[2]
Luanda is a member of theEunomia family (502),[4] a prominentfamily of stonyS-type asteroid and the largest one in the intermediate main belt with more than 5,000 members.[10]: 23 It orbits the Sun in thecentral asteroid belt at a distance of 2.1–3.1 AU once every 4 years and 3 months (1,549 days). Its orbit has aneccentricity of 0.18 and aninclination of 14° with respect to theecliptic.[1] The body'sobservation arc begins with its official discovery observation at Johannesburg in 1937.[9]
Luanda has been characterized as aL/S-type asteroid byPan-STARRS photometric survey.[8] The LCDB assumes it to be a common stonyS-type asteroid,[3] in-line with the family's overallspectral type.[10]: 23
In December 1997, a rotationallightcurve ofLuanda was obtained from photometric observations at theFélix Aguilar Observatory in Argentina . Lightcurve analysis gave arotation period of 5.360 hours with a brightness variation of 1.0magnitude (U=2).[7] In January 2007, French amateur astronomerRené Roy obtained a period of 4.141 hours with an amplitude of 0.77 magnitude (U=9-).[6] A high brightness amplitude indicates that the body has an elongated rather than spherical shape.
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Luanda measures 13.61 kilometers in diameter and its surface has analbedo of 0.36.[5]
TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for Eunomian asteroids of 0.21 – derived from15 Eunomia, the parent body of this family – and calculates a diameter of 13.88 kilometers based on anabsolute magnitude of 11.6.[3]
Thisminor planet was named after the city ofLuanda, capital ofAngola.[2] The official naming citation was published by theMinor Planet Center on 1 February 1980 (M.P.C. 5182).[11]
