|Discovered by E. F. Helin|
MPC designation 10502 Armaghobs
Observation arc 35.42 yr (12,938 days)
Named after Armagh Observatory
Asteroid group Mars-crosser asteroid
|Discovery date 22 August 1987|
Minor planet category Mars-crosser
Discovered 22 August 1987
Discoverer Eleanor F. Helin
Discovery site Palomar Observatory
|Alternative names 1987 QF6 · 1980 PJ2
Similar 4015 Wilson–Harrington, Sun, 6489 Golevka, 9969 Braille, 4769 Castalia
10502 Armaghobs, provisional designation 1987 QF6, is an eccentric, rare-type stony asteroid and Mars-crosser from the inner regions of the asteroid belt, about 3 kilometers in diameter. It was discovered by American astronomer Eleanor Helin at the U.S. Palomar Observatory in California, on 22 August 1987.
The S-type asteroid was also classified as a relatively rare Q-type body by Pan-STARRS' large-scale survey. It orbits the Sun at a distance of 1.6–3.0 AU once every 3 years and 6 months (1,282 days). Its orbit has an eccentricity of 0.32 and an inclination of 22° with respect to the ecliptic. The first precovery was taken at ESO's La Silla Observatory in 1980, extending the asteroid's observation arc by 7 years prior to its discovery.
In 2013, a rotational light-curve obtained from photometric observations at the Riverland Dingo Observatory at Moorook, South Australia, gave a rotation period of 7001249780000000000♠24.978±0.002 hours with a brightness amplitude of 0.51 in magnitude (U=2). The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20, and calculates a diameter of 3.0 kilometers based on an absolute magnitude of 15.0.
The minor planet was named after the Armagh Observatory in Northern Ireland. The present-day astronomical research institute was founded by Archbishop Richard Robinson in 1790. The Estonian astronomer Ernst Öpik, after whom 2099 Öpik is named, had been a long-time member of the Observatory. It is also known for the invention of the cup-anemometer by Thomas Robinson, the New General Catalogue compiled by John Dreyer, and Lindsay's Armagh-Dunsink-Harvard telescope. Naming citation was published on 9 January 2001 (M.P.C. 41937).