Minor planet category Main belt (Eos) Orbital period 1,943 days Orbits Sun Asteroid family Eos family | Discovery date 8 February 1889 Observation arc 122.26 yr (44655 d) Discovered 8 February 1889 Moon S/2003 (283) 1 | |
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Aphelion 3.49701 AU (523.145 Gm) Perihelion 2.59675 AU (388.468 Gm) Similar 121 Hermione, 107 Camilla, 130 Elektra, Asteroid belt, 423 Diotima | ||
283 Emma is a large asteroid of the asteroid belt. It was discovered by Auguste Charlois on February 8, 1889, in Nice, France. The reason for its name is unknown.
Measurements made with the IRAS observatory give a diameter of 145.70 ± 5.89 km and a geometric albedo of 0.03 ± 0.01. By comparison, the MIPS photometer on the Spitzer Space Telescope gives a diameter of 145.44 ± 7.72 km and a geometric albedo of 0.03 ± 0.01. When the asteroid was observed occulting a star, the results showed a diameter of 148.00 ± 16.26 km.
Satellite
A companion for 283 Emma was detected on 14 July 2003 by W. J. Merline et al. using the Keck II telescope and is designated S/2003 (283) 1. The announcement is contained in the International Astronomical Union Circular (IAUC) 8165. The satellite orbits at a semi-major axis of about 581 km with an eccenticity of 0.12. Emma has a hill sphere with a radius of about 28,000 km.