Discovery date 1 January 1998 Alternative names 1998 AA Discovered 1 January 1998 Orbits Sun Asteroid group Asteroid belt | MPC designation 23712 Willpatrick Minor planet category main-belt · Phocaea Absolute magnitude 13.5 Discovery site George Observatory | |
Discovered by W. G. Dillon
E. R. Dillon Named after William Dillon
(discoverer's son) Discoverers Elizabeth R. Dillon, William G. Dillon People also search for Sun, (39696) 1996 TO1 | ||
23712 Willpatrick, provisional designation 1998 AA, is a stony Phocaea asteroid from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 1 January 1998, by American astronomers Elizabeth and William G. Dillon at George Observatory in Needville, Texas.
The stony S-type asteroid is a member of the Phocaea family, a group of asteroids with similar orbital characteristics. It orbits the Sun at a distance of 1.8–3.0 AU once every 3 years and 8 months (1,337 days). Its orbit has an eccentricity of 0.25 and an inclination of 23° with respect to the ecliptic. The first precovery was taken during the Digitized Sky Survey at Palomar Observatory in 1954, extending Willpatrick's observation arc by 44 years prior to its official discovery observation.
A rotational light-curve was obtained by American astronomer Brian D. Warner at his Palmer Divide Observatory (716) in September 2004. The photometric observations rendered a well-defined rotation period of 7000390200000000000♠3.902±0.005 hours with a brightness variation of 0.40 magnitude (U=3). According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Willpatrick measures 7.7 kilometers in diameter and its surface has an albedo of 0.12, while the Collaborative Asteroid Lightcurve Link assumes a higher albedo of 0.23 – derived from 25 Phocaea, the namesake of the Phocaea family – and calculates a diameter of 5.3 kilometers, based on an absolute magnitude of 13.6.
The minor planet was named after the discoverer's son, William Patrick Dillon (b. 1992), who was present on the night this minor planet was discovered. His words "Daddy, I want to go home now. This place is cold and spooky." made it into the naming citation of the Minor Planet Circulars (MPCs). Naming citation was published on 28 September 2004 (M.P.C. 52769).