Discovery date 11 October 1982 Alternative names 1982 TA Discovered 11 October 1982 Orbits Sun | MPC designation 4197 Morpheus Orbital period 1,275 days Aphelion 4.07 m | |
Discovered by E. F. HelinE. Shoemaker Minor planet category Apollo · NEOMars-crosserVenus-crosser Discoverers Eugene Merle Shoemaker, Eleanor F. Helin Similar 4183 Cuno, 69230 Hermes, 1685 Toro, 4660 Nereus, 4544 Xanthus | ||
4197 Morpheus, provisional designation 1982 TA, is an extremely eccentric stony asteroid and near-Earth object from to the subgroup of Apollo asteroids, about 3 kilometers in diameter. It was discovered by American astronomers Eleanor Helin and Eugene Shoemaker at the U.S. Palomar Observatory, California, on 11 October 1982.
The asteroid orbits the Sun at a distance of 0.5–4.1 AU once every 3 years and 6 months (1,271 days). Its orbit has an eccentricity of 0.77 and an inclination of 13° with respect to the ecliptic.Due to this elongated orbit, the asteroid is both, a Mars-crosser and a Venus-crosser. Its minimum orbit intersection distance with Earth is 0.0983 AU (14,700,000 km). The first precovery was taken at the discovering observatory in 1954, extending the asteroid's observation arc by 28 years prior to its discovery.
On the SMASS taxonomic scheme, the stony S-type asteroid is classified as a Sq sub-type, which transitions to the rather rare Q-type. According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, it measures about 3.0 kilometers in diameter and its surface has a relatively high albedo of 0.28.
The asteroid has a well-defined rotation period of 3.54 hours. In 1996 during the body's close approach to Earth within 0.1 AU, a photometric light-curve analysis performed by Czech astronomer Petr Pravec at the Ondřejov Observatory gave a period of 7000353800000000000♠3.5380 hours with a brightness amplitude of 0.49 in magnitude (U=3). At the same time, astronomers at the Goldstone Observatory analysed it using radar delay-Doppler imaging. The resultant images are not very clear, but they show that the body has a roughly triangular shape, and a 3-hour rotation period. Seven years later, during the asteroid's next close approach in 2003, it was observed for five nights by Slovak astronomer Adrián Galád at the Modra Observatory. The light-curve rendered a period of 7000353870000000000♠3.5387 hours and an amplitude of 0.4 in magnitude (U=3).
The minor planet is named after Morpheus from Greek mythology. He is a god of dreams who appears in the poem Metamorphoses written by the Roman poet Ovid. He is capable to imitate any human form and to appear in dreams. It is also the name of one of the characters in the franchise The Matrix. Naming citation was published on 5 January 2015 (M.P.C. 91790).