 Animated orbit of 9950 ESA | |
| Discovery[1] | |
|---|---|
| Discovered by | C. Pollas |
| Discovery site | Caussols Obs.(010) |
| Discovery date | 8 November 1990 |
| Designations | |
| (9950) ESA | |
Named after | European Space Agency[2] |
| 1990 VB | |
| NEO · Amor[1][3][4] Mars-crosser | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 26.90 yr (9,824 days) |
| Aphelion | 3.7367AU |
| Perihelion | 1.1391 AU |
| 2.4379 AU | |
| Eccentricity | 0.5328 |
| 3.81yr (1,390 days) | |
| 17.795° | |
| 0° 15m 32.04s / day | |
| Inclination | 14.597° |
| 253.51° | |
| 103.57° | |
| Earth MOID | 0.2806 AU · 109.3LD |
| Physical characteristics | |
| Dimensions | 1.71 km(calculated)[5] 3 km(estimated)[4]: 21 |
| 6.707±0.002h[6][a] 6.7078±0.0007 h[7] 6.712±0.005 h[8][b] | |
| 0.20(assumed)[5] | |
| S (assumed)[5] | |
| 16.2[1][5] | |
9950 ESA, provisional designation1990 VB, is an eccentricasteroid and elongatednear-Earth object of theAmor group, approximately 1.7 kilometers in diameter. It was discovered on 8 November 1990, by French astronomerChristian Pollas at theCentre de recherches en géodynamique et astrométrie (Cerga) at Caussols in southeastern France.[3] It was named for theEuropean Space Agency (ESA).[2]
ESA is anAmor asteroid – a subgroup of near-Earth asteroids that approach the orbit of Earth from beyond, but do not cross it. It orbits the Sun at a distance of 1.1–3.7 AU once every 3 years and 10 months (1,390 days). Its orbit has aneccentricity of 0.53 and aninclination of 15° with respect to theecliptic.[1] The body'sobservation arc begins with its official discovery observation at Caussols in November 1990.[3]
ESA has an Earthminimum orbit intersection distance of 0.2806 AU (42,000,000 km), which corresponds to 109.3lunar distances. It approached the Earth at 0.393 AU on 18 October 1990, three weeks prior to its discovery, and made two more close approaches in August and September 2013, respectively. Its next close encounter with Earth will be in October 2032, at distance of 0.3043 AU (45,500,000 km).[1]
The eccentric asteroid is also aMars-crosser. In March 1987, it approached the Red Planet at 0.0990 AU (14,800,000 km).[1]
ESA is an assumed stonyS-type asteroid.[5]
In 2013, three rotationallightcurves ofESA were obtained from photometric observations by the EURONEAR Lightcurve Survey and by American astronomersBrian Warner andRobert Stephens at the Center for Solar System Studies (U81/U82). Lightcurve analysis gave arotation period between 6.707 and 6.712 hours with a brightness variation of 0.44 to 0.89magnitude (U=3/3/3-).[6][7][8][a][b] A high brightness amplitude typically indicates that the body's shape is irregular and elongated, rather than spherical.
In the early 1990s,David Tholen at the Institute for Astronomy of the University of Hawaii estimated a diameter of 3 kilometers forESA.[4]: 21 TheCollaborative Asteroid Lightcurve Link assumes a standardalbedo for stony asteroids of 0.20 and calculates a diameter of 1.71 kilometers based on anabsolute magnitude of 16.2.[5]
Thisminor planet was named after theEuropean Space Agency (ESA), which formed in 1974. The name was suggested by French astronomer Jean Louis Heudier, after whom the asteroid4602 Heudier was named.[2] The official naming citation was published by theMinor Planet Center on 15 December 2005 (M.P.C. 55720).[9]
