4149 Harrison, provisional designation 1984 EZ, is a stony Eunomian asteroid from the middle region of the asteroid belt, approximately 10 kilometers in diameter. The asteroid was discovered on 9 March 1984, by American astronomer Brian Skiff at Lowell's Anderson Mesa Station in Flagstaff, Arizona, and named after musician George Harrison.[8]
Orbit and classification
Harrison is a member of the Eunomia family, a large group of S-type asteroids and the most prominent family in the intermediate main-belt. It orbits the Sun in the central main-belt at a distance of 2.3–3.0 AU once every 4 years and 4 months (1,590 days). Its orbit has an eccentricity of 0.12 and an inclination of 13° with respect to the ecliptic.[1] A first precovery was taken at Palomar Observatory in 1977, extending the body's observation arc by 7 years prior to its discovery.[8]
Physical characteristics
Rotation period
A rotational lightcurve of Harrison was obtained from photometric observations by Czech astronomer Petr Pravec at Ondřejov Observatory in May 2015. It gave a well-defined rotation period of 3.7490±0.0002 hours with a brightness variation of 0.42 in magnitude (U=3).[a] During the following month, photometric observations at three Italian observatories gave a second lightcurve with a period of 3.956±0.001 hours and an amplitude of 0.37 in magnitude (U=2+).[6]
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Harrison measures 10.1 and 10.7 kilometers in diameter and its surface has an albedo of 0.19 and 0.23, respectively,[4][5] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.21 – derived from 15 Eunomia, the family's largest member and namesake – and calculates a diameter of 8.1 kilometers with an absolute magnitude of 12.76.[3]