Discovery date 25 September 1987 Alternative names 1987 SY · 1937 CA Observation arc 28.22 yr (10,306 days) Aphelion 2.29 m | Discovered 25 September 1987 Orbits Sun | |
Discovered by C. ShoemakerE. Shoemaker Discoverers Carolyn S. Shoemaker, Eugene Merle Shoemaker Similar 3671 Dionysus, 4183 Cuno, Sun, 3362 Khufu, 2101 Adonis | ||
4450 Pan, provisional designation 1987 SY, is a highly eccentric, contact-binary asteroid, classified as a near-Earth asteroid and potentially hazardous object. It belongs to the group of Apollo asteroids and measures approximately 1.1 kilometers in diameter. It was discovered on 25 September 1987, by American astronomers Eugene and Carolyn Shoemaker at the U.S Palomar Observatory in California.
The stony S-type asteroid orbits the Sun at a distance of 0.6–2.3 AU once every 633 days (1 year and 9 months). Its orbit has an eccentricity of 0.59 and an inclination of 6° with respect to the ecliptic. As an Apollo asteroid, it is an Earth-crosser and has a minimum orbit intersection distance with Earth of 0.0283 AU (4,230,000 km) or 11.0 lunar distances. In addition, due to its extremely eccentric orbit, it is also a Venus- and Mars-crosser and approaches Mercury within 20 Gm. Its first observation was made at Heidelberg Observatory in 1937, yet it remained unused and the asteroid's observation arc begins with its discovery observation in 1987.
The asteroid is a contact binary, composed of two lobes in mutual contact, held together only by their weak gravitational attraction, and typically show a dumbbell-like shape (also see 4769 Castalia). A large number of near-Earth objects are thought to be contact binaries. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 1.1 kilometers, while photometric observations by Italian Albino Carbognani at Saint-Barthelemy Observatory (B04) gave a diameter of 7000100000000000000♠1.0±0.2 kilometers.
In September 2013, a rotational light-curve of this asteroid was obtained from photometric observations by U.S. astronomer Brian D. Warner at his Palmer Divide Station in Colorado. It gave a long rotation period of 7001564800000000000♠56.48±0.02 hours with a brightness variation of 0.64 in magnitude (U=3). The well-defined period superseds two previous observations by Petr Pravec at Silvano Casulli that gave a period of 7001600000000000000♠60±12 and 7000351000000000000♠3.51±0.02 hours, respectively.(U=2/1).
The minor planet was named after Pan, the Greek god of nature, shepherds of flocks and wild animals. In art, he was represented as a horned half-man, half goat. Pan was worshiped by the citizens of Athens, after he had inspired panic in the hearts of their Persians enemies in the Battle of Marathon (also see 4356 Marathon). The modern word "panic" origins from this myth. The name Pan has also been given to Saturn XVIII, one of the moons of Saturn. Naming citation was published on 30 January 1991 (M.P.C. 17657).