Discovered by UESAC MPC designation 9617 Grahamchapman Minor planet category main-belt · Flora Orbits Sun Discovery site La Silla Observatory Discoverer UESAC | Discovery date 17 March 1993 Alternative names 1993 FA5 · 1991 RN18 Discovered 17 March 1993 Asteroid family Flora family Moon S/2006 (9617) 1 | |
Named after Graham Chapman
(Monty Python) Similar 1338 Duponta, Asteroid belt, Solar System, Sun, 107 Camilla | ||
9617 Grahamchapman, provisional designation 1993 FA5, is a binary Florian asteroid from the inner regions of the asteroid belt, approximately 2.8 kilometers in diameter. It was discovered on 17 March 1993, during the Uppsala–ESO Survey of Asteroids and Comets (UESAC) at ESO's La Silla Observatory in northern Chile.
The S-type asteroid is a member of the Flora family, one of the largest collisional groups of stony asteroids in the main-belt. It orbits the Sun at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,212 days). Its orbit has an eccentricity of 0.11 and an inclination of 6° with respect to the ecliptic. The first precovery was taken at Palomar Observatory in 1951, extending the asteroid's observation arc by 42 years prior to its discovery.
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the asteroid measures 2.84 kilometers in diameter and its surface has an albedo of 0.245. The Collaborative Asteroid Lightcurve Link agrees with Petr Pravec's revised NEOWISE data and gives an albedo of 0.224 with a diameter of 2.85 kilometers, based on an absolute magnitude of 14.97.
In February 2006, observations by the Ondřejov NEO Photometric Program determined that this asteroid is orbited by a moon. The moon is about a quarter the size of Grahamchapman, and orbits it about once every 19 hours, 23 minutes, and 5 seconds. The light-curve study also showed that Grahamchapman itself has a rotation period of 2.28561 hours with a brightness variation of 0.10 magnitude (U=3). A second photometric observation in December 2008, gave an identical period with an amplitude of 0.11 magnitude (U=3). A low brightness amplitude typically indicates that the body has a nearly spheroidal shape.
This minor planet is named after the comic actor Graham Chapman (1941–1989). It is the first in a series of six asteroids carrying the names of members of the Monty Python comedy troupe, the others being 9618 Johncleese, 9619 Terrygilliam, 9620 Ericidle, 9621 Michaelpalin and 9622 Terryjones. Naming citation was published on 20 March 2000 (M.P.C. 39653).