Discovery date 22 September 1987 Alternative names 1987 SB · 1974 DN1 Discovered 22 September 1987 Orbits Sun | MPC designation 4486 Mithra Minor planet category Apollo · NEO · PHA Aphelion 3.66 m Asteroid group Asteroid belt | |
Discovered by E. W. Elst
V. G. Shkodrov Named after Mithra
(proto-Indo-Iranian religion) Discoverers Vladimir Shkodrov, Eric Walter Elst Discovery site Siding Spring Observatory, Rozhen Observatory Similar 4183 Cuno, 4660 Nereus, 1685 Toro, 4544 Xanthus, 69230 Hermes | ||
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.
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 an 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 0.0462 AU or 18 lunar distances. On 14 August 2000, it passed 0.0465 AU (6,960,000 km) from Earth. 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.
Radar imaging using a delay-Doppler technique at the Arecibo and Goldstone observatories rendered a rotation period of 7001675000000000000♠67.5±6 hours. 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). A large number of near-Earth objects are believed to be contact-binaries.
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.
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 religions shared similar characteristics such as elevation and 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. Naming citation was published on 5 September 1990 (M.P.C. 16885).