4486 Mithra

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4486 Mithra
Discovery [1]
Discovered by E. W. Elst
V. G. Shkodrov
Discovery site Rozhen Obs. – Smolyan
Discovery date 22 September 1987
MPC designation 4486 Mithra
Named after
(proto-Indo-Iranian religion)[2]
1987 SB · 1974 DN1
Apollo · NEO · PHA
Orbital characteristics[1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc 29.04 yr (10,607 days)
Aphelion 3.6579 AU
Perihelion 0.7417 AU
2.1998 AU
Eccentricity 0.6628
3.26 yr (1,192 days)
0° 18m 7.56s / day
Inclination 3.0393°
Earth MOID 0.0463 AU
Physical characteristics
Dimensions 1.849±0.022 km[3]
2.25 km (calculated)[4]
67.5±6 h[5]
100 h[6]
0.20 (assumed)[4]

4486 Mithra, provisional designation 1987 SB, is an eccentric asteroid and slow rotator, classified as near-Earth asteroid and potentially hazardous object, approximately 2 kilometers in diameter. It belongs to the Apollos group of asteroids and is a suspected contact-binary. It was discovered on 22 September 1987, by Belgian astronomer Eric Elst and Bulgarian astronomer Vladimir Shkodrov at Rozhen Observatory, in the Smolyan Province of Bulgaria.[8]

The S-type orbits the Sun at a distance of 0.7–3.7 AU once every 3 years and 3 months (1,192 days). Its orbit has a very high eccentricity of 0.66 and an inclination of 3° with respect to the ecliptic. As a potentially hazardous asteroid, it has a low minimum orbit intersection distance with Earth of 0.0463 AU or 18.0 lunar distances.[1] On 14 August 2000, it passed 0.0465 AU (6,960,000 km) from Earth.[9] The first used precovery was taken at the Japanese Kiso Observatory in January 1987, extending the asteroid's observation arc by 8 years prior to its discovery.[8]

Radar imaging using a delay-Doppler technique at the Arecibo and Goldstone observatories rendered a rotation period of 67.5±6 hours.[5] Based on the radar analysis, the asteroid is also a strong candidate for a contact binary, which is composed of two distinct lobes in mutual contact, held together by their weak gravitational attraction. They typically show a bifurcated, dumbbell-like shape (also see 4769 Castalia).[5][10] A large number of near-Earth objects are believe to be contact-binaries.[11]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures 1.85 kilometers in diameter and its surface has a high albedo of 0.297, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 2.25 kilometer, based on an absolute magnitude of 15.6.[3][4]

The minor planet was named after Mithra (also see Mitra), deity in the proto-Indo-Iranian religion. The mystery religion of Mithraism was practiced in the Roman Empire between the 1st and 4th century. Considered to be a rival of early Christianity, both religion shared similar characteristics such as elevation and a the ritual of baptism. In the Hellenistic world, Mithra was conflated with Apollo. The asteroid 1862 Apollo is the namesake of this asteroid's orbital group.[2] Naming citation was published on 5 September 1990 (M.P.C. 16885).[12]


  1. ^ a b c d "JPL Small-Body Database Browser: 4486 Mithra (1987 SB)" (2016-02-13 last obs.). Jet Propulsion Laboratory. Retrieved 10 August 2016. 
  2. ^ a b Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (4486) Mithra. Springer Berlin Heidelberg. p. 386. ISBN 978-3-540-00238-3. Retrieved 10 August 2016. 
  3. ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407free to read. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 10 August 2016. 
  4. ^ a b c d e "LCDB Data for (4486) Mithra". Asteroid Lightcurve Database (LCDB). Retrieved 10 August 2016. 
  5. ^ a b c Brozovic, Marina; Benner, Lance A. M.; Magri, Christopher; Ostro, Steven J.; Scheeres, Daniel J.; Giorgini, Jon D.; et al. (July 2010). "Radar observations and a physical model of contact binary Asteroid 4486 Mithra". Icarus. 208 (1): 207–220. Bibcode:2010Icar..208..207B. doi:10.1016/j.icarus.2010.01.035. Retrieved 10 August 2016. 
  6. ^ Ostro, S. J.; Hudson, R. S.; Benner, L. A. M.; Nolan, M. C.; Margot, J.-L.; Giorgini, J. D.; et al. (October 2000). "Radar Observations of Asteroid 4486 Mithra". American Astronomical Society. 32: 1003. Bibcode:2000DPS....32.0807O. Retrieved 10 August 2016. 
  7. ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762free to read. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 10 August 2016. 
  8. ^ a b "4486 Mithra (1987 SB)". Minor Planet Center. Retrieved 10 August 2016. 
  9. ^ "JPL Small-Body Database Browser: 4486 Mithra (1987 SB)". Jet Propulsion Laboratory. Retrieved 10 August 2016. 
  10. ^ Lance A. M. Benner (2013-11-18). "Binary and Ternary near-Earth Asteroids detected by radar". NASA/JPL Asteroid Radar Research. Retrieved 2014-03-01. 
  11. ^ Michael Busch (12 March 2012). "Near-Earth Asteroids and Radar Speckle Tracking" (PDF). Retrieved 10 August 2016. 
  12. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 10 August 2016. 

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