astro.wikisort.org - Asteroid

9950 ESA, provisional designation 1990 VB, is an eccentric asteroid and elongated near-Earth object of the Amor group, approximately 1.7 kilometers in diameter. It was discovered on 8 November 1990, by French astronomer Christian Pollas at the Centre de recherches en géodynamique et astrométrie (Cerga) at Caussols in southeastern France.[3] It was named for the European Space Agency (ESA).[2]

9950 ESA

Animated orbit of 9950 ESA
Discovery [1]
Discovered by	C. Pollas
Discovery site	Caussols Obs. (010)
Discovery date	8 November 1990
Designations
MPC designation	(9950) ESA
Named after	European Space Agency [2]
Alternative designations	1990 VB
Minor planet category	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	3.7367 AU
Perihelion	1.1391 AU
Semi-major axis	2.4379 AU
Eccentricity	0.5328
Orbital period (sidereal)	3.81 yr (1,390 days)
Mean anomaly	17.795°
Mean motion	0° 15m 32.04s / day
Inclination	14.597°
Longitude of ascending node	253.51°
Argument of perihelion	103.57°
Earth MOID	0.2806 AU · 109.3 LD
Physical characteristics
Dimensions	1.71 km (calculated)[5] 3 km (estimated)[4]: 21
Synodic rotation period	6.707±0.002 h[6][lower-alpha 1] 6.7078±0.0007 h[7] 6.712±0.005 h[8][lower-alpha 2]
Geometric albedo	0.20 (assumed)[5]
Spectral type	S (assumed)[5]
Absolute magnitude (H)	16.2[1][5]

Orbit and classification

ESA is an Amor 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 an eccentricity of 0.53 and an inclination of 15° with respect to the ecliptic.[1] The body's observation arc begins with its official discovery observation at Caussols in November 1990.[3]

Close approaches

ESA has an Earth minimum orbit intersection distance of 0.2806 AU (42,000,000 km), which corresponds to 109.3 lunar 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 a Mars-crosser. In March 1987, it approached the Red Planet at 0.0990 AU (14,800,000 km).[1]

Physical characteristics

ESA is an assumed stony S-type asteroid.[5]

Rotation period

In 2013, three rotational lightcurves of ESA were obtained from photometric observations by the EURONEAR Lightcurve Survey and by American astronomers Brian Warner and Robert Stephens at the Center for Solar System Studies (U81/U82). Lightcurve analysis gave a rotation period between 6.707 and 6.712 hours with a brightness variation of 0.44 to 0.89 magnitude (U=3/3/3-).[6][7][8][lower-alpha 1][lower-alpha 2] A high brightness amplitude typically indicates that the body's shape is irregular and elongated, rather than spherical.

Diameter and albedo

In the early 1990s, David Tholen at the Institute for Astronomy of the University of Hawaii estimated a diameter of 3 kilometers for ESA.[4]^: 21 The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 1.71 kilometers based on an absolute magnitude of 16.2.[5]

Naming

This minor planet was named after the European Space Agency (ESA), which formed in 1974. The name was suggested by French astronomer Jean Louis Heudier, after whom the asteroid 4602 Heudier was named.[2] The official naming citation was published by the Minor Planet Center on 15 December 2005 (M.P.C. 55720).[9]

Notes

References

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• 9950 ESA at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
• 9950 ESA at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical Properties · Summary
• 9950 ESA at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

На других языках

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- [en] 9950 ESA

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[ru] (9950) ЕКА

(9950) ЕКА (англ. ESA) — околоземный астероид из группы Амура (III), который был открыт 8 ноября 1990 года французским астрономом Кристианом Полласом в исследовательском центре CERGA и назван в честь Европейского космического агентства (ESA).

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