3290 Azabu, provisional designation 1973 SZ1, is a dynamical Hildian asteroid from the outermost regions of the asteroid belt, approximately 10–20 kilometers (6–10 miles) in diameter. It was discovered on 19 September 1973, by Dutch astronomers Ingrid and Cornelis van Houten at Leiden, and Tom Gehrels the Palomar Observatory.[1] The asteroid has a rotation period of 7.67 hours.[3] It was named after the former city district of Tokyo, Azabu.[1]
Orbit and classification
Azabu is a member of the dynamical Hilda group, located beyond the actual core region of the asteroid belt, and locked in a 3:2 orbital resonance with the gas giant Jupiter. This means that for every 2 orbits Jupiter completes around the Sun, a Hildian asteroid will complete 3 orbits.[2] While it belongs to the dynamical Hilda group, Azabu, is not a member of the Hilda family (001), but an asteroid of the background population.[4]
This asteroid orbits the Sun in the outer main-belt at a distance of 3.5–4.5 AU once every 7 years and 11 months (2,891 days; semi-major axis of 3.97 AU). Its orbit has an eccentricity of 0.13 and an inclination of 3° with respect to the ecliptic.[2] The body's observation arc begins with a precovery taken at Palomar in April 1954, or 29 years prior to its official discovery observation.[1]
The asteroid has been characterized as an XL-type by Pan-STARRS and in the SDSS-based taxonomy.[8][9] It is also characterized as a carbonaceous C-type asteroid in the SDSS-MFB (Masi Foglia Binzel) taxonomy.[3][b]
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Azabu measures 10.2 kilometers in diameter and its surface has an albedo between 0.32.[5] The Collaborative Asteroid Lightcurve Link assumes a much lower carbonaceous standard albedo of 0.057 (based on the Masi Foglia Binzel taxonomy) and consequently calculates a much larger diameter of 21.16 kilometers with an absolute magnitude of 12.1.[3]
^ abLightcurve plot of (3290) Azabu, B. D. Warner at the CS3 (April 2017). Rotation period 7.670±0.005 hours with a brightness amplitude of 0.23±0.02 mag. Total of 190 points. Quality code of 3-. Summary figures at the LCDB.
^ abSearch for Unusual Spectroscopic Candidates Among 40313 minor planets from the 3rd Release of the Sloan Digital Sky Survey Moving Object Catalog (publication). SDSS-MFB (Masi Foglia Binzel) taxonomy (catalog).