| Discovery[1] | |
|---|---|
| Discovered by | C.-I. Lagerkvist |
| Discovery site | Kvistaberg Stn. |
| Discovery date | 2 March 1976 |
| Designations | |
| (5080) Oja | |
Named after | Tarmo Oja[1] (Estonian–Swedish astronomer) |
| 1976 EB · 1951 WO 1951 XA · 1988 XH A924 SB | |
| main-belt[1][2] · (inner) Flora[3][4] · Matterania | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 92.68yr (33,852 d) |
| Aphelion | 2.5215AU |
| Perihelion | 1.9617 AU |
| 2.2416 AU | |
| Eccentricity | 0.1249 |
| 3.36 yr (1,226 d) | |
| 255.46° | |
| 0° 17m 37.32s / day | |
| Inclination | 5.4503° |
| 344.79° | |
| 89.320° | |
| Physical characteristics | |
| 6.94±1.26 km[5] 7.766±0.080 km[6] 8.377 km[7] 8.38 km(taken)[3] 8.399±0.049 km[8] | |
| 7.2220±0.0004 h[9] 7.2222±0.00003 h[a] 7.7 h[10] | |
| 0.1573[7] 0.1741±0.0430[8] 0.218±0.021[6] 0.31±0.15[5] | |
| S[11] · S(assumed)[3] | |
| 12.52±0.04(R)[a] · 12.6[2] 12.9[8] · 12.97[5] · 13.01[3] 13.01±0.064[7] 13.15±0.12[11] | |
5080 Oja, provisional designation1976 EB, is a stony Florianasteroid from the inner regions of theasteroid belt, approximately 8 kilometers in diameter. It was discovered on 2 March 1976, by astronomerClaes-Ingvar Lagerkvist at theKvistaberg Station of theUppsala Observatory in Sweden. In 1992, it was named after Estonian–Swedish astronomerTarmo Oja.[1] TheS-type asteroid has arotation period of 7.222 hours.[3]
Oja is a member of theFlora family (402),[3][4] a giantasteroid family and the largest family of stony asteroids in the main belt.[12] It orbits the Sun in theinner main belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,226 days;semi-major axis of 2.24 AU). Its orbit has aneccentricity of 0.12 and aninclination of 5° with respect to theecliptic.[2]
On 29 September 1924, the asteroid was first observed asA924 SB atHeidelberg Observatory, where the body'sobservation arc begins two days later on 1 October 1924.[1]
Oja has been characterized as a common, stonyS-type asteroid byPan-STARRS's photometric survey, in line with the overallspectral type of the Flora family.[12]: 23
In January 2006, a rotationallightcurve ofOja was obtained from photometric observations by an international collaboration of astronomers includingPetr Pravec atOndřejov Observatory andDonald Pray at Carbuncle Hill Observatory (912). The consolidated lightcurve analysis gave arotation period of 7.222 hours and a brightness variation between 0.31 and 0.39magnitude (U=3/3).[9][a] The result supersedes a period of 7.7 hours obtained by the discoverer (Claes-Ingvar Lagerkvist) in March 1976 (U=2).[10]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Oja measures between 6.94 and 8.399 kilometers in diameter and its surface has analbedo between 0.1573 and 0.31.[5][6][7][8] TheCollaborative Asteroid Lightcurve Link adopts an albedo of 0.1573 from Pravec's revised WISE data and uses a diameter of 8.38 kilometers based on anabsolute magnitude of 13.01.[3]
Thisminor planet was named after the Swedish astronomer of Estonian descentTarmo Oja (born 1934), who was a professor in astronomy atUppsala University and the director of the discoveringKvistaberg Station during 1970–1999. His research included the structure of galaxies andvariable stars. The official naming citation was published by theMinor Planet Center on 14 July 1992 (M.P.C. 20522).[13]
