802 Epyaxa

From Wikipedia, the free encyclopedia
Jump to: navigation, search
802 Epyaxa
Discovery [1]
Discovered by M. Wolf
Discovery site Heidelberg Obs.
Discovery date 20 March 1915
MPC designation 802 Epyaxa
Named after
(Queen, 400 BC)[2]
1915 WR · 1930 YK
1931 AX · 1970 AM1
1972 XW · 1977 FG3
main-belt · Flora[3]
Orbital characteristics[1]
Epoch 27 June 2015 (JD 2457200.5)
Uncertainty parameter 0
Observation arc 100.74 yr (36,795 days)   
Aphelion 2.3689 AU
Perihelion 2.0230 AU
2.1960 AU
Eccentricity 0.0787
3.25 yr (1,189 days)
Inclination 5.2023°
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]
0.24 (assumed)[3]

802 Epyaxa, provisional designation 1915 WR, is a stony asteroid from the inner regions of the asteroid belt, about 7 kilometers in diameter. It was discovered by German astronomer Max Wolf at the Heidelberg Observatory in southern Germany, on 20 March 1915.[12]

The 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 light-curve 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]

The 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]


  1. ^ a b c d "JPL Small-Body Database Browser: 802 Epyaxa (1915 WR)" (2015-12-16 last obs.). Jet Propulsion Laboratory. Retrieved January 2016. 
  2. ^ a b Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names – (802) Epyaxa. Springer Berlin Heidelberg. p. 75. ISBN 978-3-540-29925-7. Retrieved January 2016. 
  3. ^ a b c d e "LCDB Data for (802) Epyaxa". Asteroid Lightcurve Database (LCDB). Retrieved January 2016. 
  4. ^ 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 January 2016. 
  5. ^ Warner, Brian D. (July 2009). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2008 December - 2009 March". Bulletin of the Minor Planets (Section of the Association of Lunar and Planetary Observers) 36 (3): 109–116. Bibcode:2009MPBu...36..109W. ISSN 1052-8091. Retrieved January 2016. 
  6. ^ Bennefeld, Craig; Aguilar, Vanessa; Cooper, Terrance; Hupp, William; Pecha, Jeane; Soar, Elysabeth (July 2009). "Asteroid Lightcurve Analysis at Ricky Observatory". Bulletin of the Minor Planets (Section of the Association of Lunar and Planetary Observers) 36 (3): 123–124. Bibcode:2009MPBu...36..123B. ISSN 1052-8091. Retrieved January 2016. 
  7. ^ Warner, Brian D. (April 2012). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2011 September - December". Bulletin of the Minor Planets (Section of the Association of Lunar and Planetary Observers) 39 (2): 69–80. Bibcode:2012MPBu...39...69W. ISSN 1052-8091. Retrieved January 2016. 
  8. ^ 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 January 2016. 
  9. ^ Stephens, Robert D. (April 2015). "Asteroids Observed from CS3: 2014 October - December". Bulletin of the Minor Planets (Section of the Association of Lunar and Planetary Observers) 42 (2): 104–106. Bibcode:2015MPBu...42..104S. ISSN 1052-8091. Retrieved January 2016. 
  10. ^ 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 January 2016. 
  11. ^ Hanus, J.; Durech, J.; Oszkiewicz, D. A.; Behrend, R.; Carry, B.; Delbo', M.; et al. (October 2015). "New and updated convex shape models of asteroids based on optical data from a large collaboration network". eprint arXiv:1510.07422. arXiv:1510.07422. Bibcode:2015arXiv151007422H. Retrieved January 2016. 
  12. ^ "802 Epyaxa (1915 WR)". Minor Planet Center. Retrieved January 2016. 

External links[edit]