Astronomy:(8201) 1994 AH2
| Discovery[1] | |
|---|---|
| Discovered by | G. J. Garradd |
| Discovery site | Siding Spring Obs. |
| Discovery date | 5 January 1994 |
| Designations | |
| (8201) 1994 AH2 | |
| 1994 AH2 | |
| Minor planet category | Apollo · NEO[1] Alinda group |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 34.86 yr (12,731 days) |
| |{{{apsis}}}|helion}} | 4.3322 AU |
| |{{{apsis}}}|helion}} | 0.7436 AU |
| 2.5379 AU | |
| Eccentricity | 0.7070 |
| Orbital period | 4.04 yr (1,477 days) |
| Mean anomaly | 285.46° |
| Mean motion | 0° 14m 37.68s / day |
| Inclination | 9.5538° |
| Longitude of ascending node | 164.12° |
| 25.120° | |
| Earth MOID | 0.1012 AU · 39.4 LD |
| Jupiter MOID | 0.6611 AU |
| Physical characteristics | |
| Dimensions | 1.859±0.183 km[2][3] 2.17 km (calculated)[4] 2.2 km[5] |
| Rotation period | 23.949 h[5][6] 24 h[lower-alpha 1] |
| Geometric albedo | 0.15 (estimated)[5] 0.154±0.042[2][3] 0.18 (assumed)[4] |
| SMASS=O[1] · O[4][5] | |
| Absolute magnitude (H) | 15.8[1][4] · 16.3[2][5] |
(8201) 1994 AH2 is a highly eccentric, rare-type asteroid, classified as near-Earth object of the Apollo group of asteroids, approximately 2 kilometers in diameter. It was discovered on 5 January 1994, by Australian amateur astronomer Gordon Garradd during the AANEAS survey at the Siding Spring Observatory, Australia.[7] It has an Earth minimum orbit intersection distance of 0.1 astronomical unit|AU (15 million km) and is associated with the Beta Taurids daytime meteor shower.[8]
Orbit and classification
The asteroid orbits the Sun at a distance of 0.7–4.3 AU once every 4.04 years (1,477 days). Its orbit has an eccentricity of 0.71 and an inclination of 10° with respect to the ecliptic.[1] It is a member of the Alinda group of asteroids with a 3:1 resonance with Jupiter that has excited the eccentricity of the orbit over the eons.[9] As an Alinda asteroid it makes approaches to Jupiter, Earth, and Venus.[10]
1994 AH2 has an Earth minimum orbital intersection distance of 0.1012 AU (15,100,000 km), which corresponds to 39.4 lunar distances. Due to its elongated orbit, it also approaches the orbit of Jupiter within 0.1022 AU (15,300,000 km).[1] On 4 January 2079, it will pass 0.3595 astronomical unit|AU (53,800,000 km) from the Earth.[10]
A first precovery was taken at the discovering observatory in 1981, extending the asteroid's observation arc by 13 years prior to its discovery.[7]
Physical characteristics
In the SMASS classification, 1994 AH2 is characterized as a rare O-type asteroid.[1]
Rotation period
In the late 1990s, Czech astronomer Petr Pravec obtained two rotational lightcurves for this asteroid from photometric observations taken at the Ondřejov Observatory, Czech Republic. They gave a longer-than average rotation period of 23.949 and 24 hours with a brightness variation of 0.27 and 0.3 magnitude, respectively ({{{1}}}).[6][lower-alpha 1]
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures 1.86 kilometers in diameter and its surface has an albedo of 0.154.[2][3] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.18 and calculates a diameter of 2.17 kilometers, based on an absolute magnitude of 15.8.[4] American astronomer Richard Binzel gives a diameter of 2.2 kilometers.[5]
Naming
As of 2017, 1994 AH2 remains unnamed.[7]
Notes
- ↑ 1.0 1.1 Pravec (1998) web: Observation from 15 July 1998. Rotation period 24 hours with a brightness amplitude of 0.3 mag. No quality rating available. Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (8201) and Pravec, P.; Wolf, M.; Sarounova, L. (1998)
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 "JPL Small-Body Database Browser: 8201 (1994 AH2)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2008201;cad=1. Retrieved 26 May 2017.
- ↑ 2.0 2.1 2.2 2.3 Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D. et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal 741 (2): 25. doi:10.1088/0004-637X/741/2/90. Bibcode: 2011ApJ...741...90M.
- ↑ 3.0 3.1 3.2 Mainzer, A.; Grav, T.; Bauer, J.; Masiero, J.; McMillan, R. S.; Cutri, R. M. et al. (December 2011). "NEOWISE Observations of Near-Earth Objects: Preliminary Results". The Astrophysical Journal 743 (2): 17. doi:10.1088/0004-637X/743/2/156. Bibcode: 2011ApJ...743..156M.
- ↑ 4.0 4.1 4.2 4.3 4.4 "LCDB Data for (8201)". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=8201%7C. Retrieved 1 September 2016.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 Binzel, R. P.; Lupishko, D.; di Martino, M.; Whiteley, R. J.; Hahn, G. J. (March 2002). "Physical Properties of Near-Earth Objects". Asteroids III: 255–271. Bibcode: 2002aste.book..255B. http://www.lpi.usra.edu/books/AsteroidsIII/pdf/3048.pdf. Retrieved 1 September 2016.
- ↑ 6.0 6.1 Pravec, Petr; Sarounová, Lenka; Wolf, Marek (December 1996). "Lightcurves of 7 Near-Earth Asteroids". Icarus 124 (2): 471–482. doi:10.1006/icar.1996.0223. Bibcode: 1996Icar..124..471P.
- ↑ 7.0 7.1 7.2 "8201 (1994 AH2)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=8201. Retrieved 1 September 2016.
- ↑ Babadzhanov, P. B. (2001). "Search for meteor showers associated with Near-Earth Asteroids". Astronomy and Astrophysics 373 (1): 329–335. doi:10.1051/0004-6361:20010583. Bibcode: 2001A&A...373..329B.
- ↑ John S Lewis (2015-08-03). "The Alinda Family of Asteroids". http://www.johnslewis.com/2015/08/the-alinda-family-of-asteroids.html. Retrieved 2019-06-26.
- ↑ 10.0 10.1 "JPL Close-Approach Data: 8201 (1994 AH2)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=8201;cad=1#cad. Retrieved 1 September 2016.
External links
- AANEAS: A Valedictory Report, AANEAS Discoveries 1990-96
- Asteroid Lightcurve Database (LCDB), query form (info )
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- (8201) 1994 AH2 at AstDyS-2, Asteroids—Dynamic Site
- (8201) 1994 AH2 at ESA–space situational awareness
- (8201) 1994 AH2 at the JPL Small-Body Database
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