7066 Nessus
7066 Nessus is a very red centaur on an eccentric orbit, located beyond Saturn in the outer Solar System. It was discovered on 26 April 1993, by astronomers of the Spacewatch program at the Kitt Peak National Observatory in Tucson, Arizona. The dark and reddish minor planet is likely elongated and measures approximately in diameter. It was named after Nessus from Greek mythology.
Orbit and classification
Nessus is a centaur, a dynamically unstable population of minor planets between the classical asteroids and the trans-Neptunian objects. It orbits the Sun at a distance of 11.9–37.4 AU once every 122 years and 4 months. Its orbit has an eccentricity of 0.52 and an inclination of 16° with respect to the ecliptic. At its perihelion, it moves much closer to the Sun than Uranus but not as close as Saturn, while at its aphelion, it moves out well beyond the orbit of Neptune.The orbits of centaurs are unstable due to perturbations by the giant planets. Nessus is an "SE object" because currently Saturn controls its perihelion and its aphelion is within the Kuiper belt. It is estimated to have a relatively long orbital half-life of about 4.9 million years. Fifty clones of the orbit of Nessus suggest that it will not pass within 1 AU of any planet for at least 20,000 years.
Discovery and naming
Nessus was discovered by David Rabinowitz, working with the Spacewatch program, at Kitt Peak National Observatory on 26 April 1993. The discovery was announced on 13 May 1993 in an IAU Circular of the Central Bureau for Astronomical Telegrams. It was the third discovery of a centaur after 2060 Chiron and 5145 Pholus, discovered by Charles Kowal and David Rabinowitz in 1977 and 1992, respectively. The body's observation arc begins with its official discovery observation at Kitt Peak in April 1993.This minor planet was named after Nessus, a centaur from Greek mythology, who poisoned and was killed by the divine hero Heracles. The official was published by the Minor Planet Center on 22 April 1997.
A symbol derived from that for 2060 Chiron, , was devised in the late 1990s by German astrologer Robert von Heeren. It replaces Chiron's K with an N for Nessus.