802 Epyaxa, provisional designation 1915 WR, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 7.5 kilometers in diameter. It was discovered by German astronomer Max Wolf at the Heidelberg Observatory in southern Germany, on 20 March 1915.[12]
 Modelled shape of Epyaxa from its lightcurve | |
| Discovery [1] | |
|---|---|
| Discovered by | M. F. Wolf |
| Discovery site | Heidelberg Obs. |
| Discovery date | 20 March 1915 |
| Designations | |
| (802) Epyaxa | |
| Pronunciation | /ɛpiˈæksə/ |
Named after | Epyaxa (Queen, 400 BC)[2] |
| 1915 WR · 1930 YK 1931 AX · 1970 AM1 1972 XW · 1977 FG3 | |
| main-belt · Flora [3] | |
| Orbital characteristics [1] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 101.08 yr (36920 d) |
| Aphelion | 2.3696 AU (354.49 Gm) |
| Perihelion | 2.0225 AU (302.56 Gm) |
| 2.1960 AU (328.52 Gm) | |
| Eccentricity | 0.079036 |
| 3.25 yr (1188.7 d) | |
| 100.80° | |
| 0° 18m 10.296s / day | |
| Inclination | 5.2028° |
| 7.8338° | |
| 115.75° | |
| Physical characteristics | |
| Dimensions | 7.423±0.193 km[4] 7.82 km (calculated)[3] |
| 4.392±0.002 h[5] 4.389±0.002 h[6] 4.394±0.005 h[7] 4.389±0.005 h[8] 4.389±0.001 h[9] 4.3902±0.0006 h[10] 4.39012±0.00005 h[11] 4.392 h (0.1830 d)[1] | |
| 0.2923±0.0802[4] 0.24 (assumed)[3] | |
| S [3] | |
| 12.7[1] | |
Description
editThe S-type asteroid is a member of the Flora family, one of the largest groups of stony asteroids in the main-belt. It orbits the Sun at a distance of 2.0–2.4 AU once every 3 years and 3 months (1,189 days). Its orbit shows an eccentricity of 0.08 and is tilted by 5 degrees to the plane of the ecliptic.[1] From 2009 to 2014, seven photometric lightcurve analysis rendered a well-defined, concurring rotation period of 4.39 hours (also see adjunct infobox).
According to the survey carried out by the U.S. Wide-field Infrared Survey Explorer with its NEOWISE mission, the asteroid's surface has a relatively high albedo of 0.29, while the Collaborative Asteroid Lightcurve Link assumes a more moderate value of 0.24, which is also identical to the albedo of the Flora family's namesake, the asteroid 8 Flora.[3][4]
This minor planet was named after Epyaxa (Ἐπύαξα), wife of King Syennesis and queen of the Kingdom of Cilicia in South Asia Minor in the 5th century BCE. The couple supported the revolt of Cyrus the Younger against his brother Artaxerxes II of Persia, after whom the minor planet 7212 Artaxerxes is named. Epyaxa had her own army and her own lavish budget to spend. Her Kingdom lost its independence and became a Persian satrapy of the Achaemenid Empire after the defeat of Cyrus.[2]
References
edit- ^ a b c d e "JPL Small-Body Database Browser: 802 Epyaxa (1915 WR)" (2015-12-16 last obs.). Jet Propulsion Laboratory. Retrieved 4 May 2016.
- ^ a b Schmadel, Lutz D. (2003). "(802) Epyaxa". Dictionary of Minor Planet Names – (802) Epyaxa. Springer Berlin Heidelberg. p. 75. doi:10.1007/978-3-540-29925-7_803. ISBN 978-3-540-29925-7.
- ^ a b c d e "LCDB Data for (802) Epyaxa". Asteroid Lightcurve Database (LCDB). Retrieved 5 January 2016.
- ^ a b c 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. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 5 January 2016.
- ^ Warner, Brian D. (July 2009). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2008 December - 2009 March". The Minor Planet Bulletin. 36 (3): 109–116. Bibcode:2009MPBu...36..109W. ISSN 1052-8091. Retrieved 5 January 2016.
- ^ Bennefeld, Craig; Aguilar, Vanessa; Cooper, Terrance; Hupp, William; Pecha, Jeane; Soar, Elysabeth (July 2009). "Asteroid Lightcurve Analysis at Ricky Observatory". The Minor Planet Bulletin. 36 (3): 123–124. Bibcode:2009MPBu...36..123B. ISSN 1052-8091. Retrieved 5 January 2016.
- ^ Warner, Brian D. (April 2012). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2011 September - December". The Minor Planet Bulletin. 39 (2): 69–80. Bibcode:2012MPBu...39...69W. ISSN 1052-8091. Retrieved 5 January 2016.
- ^ Kryszczynska, A.; Colas, F.; Polinska, M.; Hirsch, R.; Ivanova, V.; Apostolovska, G.; et al. (October 2012). "Do Slivan states exist in the Flora family?. I. Photometric survey of the Flora region". Astronomy and Astrophysics. 546: 51. Bibcode:2012A&A...546A..72K. doi:10.1051/0004-6361/201219199. Retrieved 5 January 2016.
- ^ Stephens, Robert D. (April 2015). "Asteroids Observed from CS3: 2014 October - December". The Minor Planet Bulletin. 42 (2): 104–106. Bibcode:2015MPBu...42..104S. ISSN 1052-8091. Retrieved 5 January 2016.
- ^ Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 5 January 2016.
- ^ Hanus, J.; Durech, J.; Oszkiewicz, D. A.; Behrend, R.; Carry, B.; Delbo', M.; et al. (2016). "New and updated convex shape models of asteroids based on optical data from a large collaboration network". Astronomy & Astrophysics. 586: A108. arXiv:1510.07422. Bibcode:2016A&A...586A.108H. doi:10.1051/0004-6361/201527441.
- ^ "802 Epyaxa (1915 WR)". Minor Planet Center. Retrieved 5 January 2016.
External links
edit- Lightcurve plot of 802 Epyaxa, Palmer Divide Observatory, B. D. Warner (2011)
- 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
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- 802 Epyaxa at AstDyS-2, Asteroids—Dynamic Site
- 802 Epyaxa at the JPL Small-Body Database
