| Discovery[1] | |
|---|---|
| Discovered by | C. J. van Houten I. van Houten-G. T. Gehrels |
| Discovery site | Palomar Obs. |
| Discovery date | 19 September 1973 |
| Designations | |
| (3290) Azabu | |
Named after | Azabu[1] (City district of Tokyo) |
| 1973 SZ1 · 1982 VX2 | |
| main-belt · (outer)[2] Hilda[1][3] · background[4] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 63.06yr (23,034 d) |
| Aphelion | 4.4853AU |
| Perihelion | 3.4579 AU |
| 3.9716 AU | |
| Eccentricity | 0.1293 |
| 7.92 yr (2,891 d) | |
| 44.445° | |
| 0° 7m 28.2s / day | |
| Inclination | 2.7728° |
| 75.105° | |
| 110.73° | |
| Jupiter MOID | 0.4837 AU |
| TJupiter | 3.0410 |
| Physical characteristics | |
| 10.185±0.504 km[5] 21.16 km(calculated)[3] | |
| 7.670±0.005 h[6][a] 12 h(poor)[7] | |
| 0.057(assumed)[3] 0.32±0.08[5] 0.324±0.082[5] | |
| XL(SDSS-MOC)[8] XL(Pan-STARRS)[9] C(SDSS-MFB)[3][b] | |
| 11.81[5] 12.1[2][3] 12.31±0.23[9] | |
3290 Azabu, provisional designation1973 SZ1, is a dynamical Hildianasteroid from the outermost regions of theasteroid belt, approximately 10–20 kilometers (6–10 miles) in diameter. It was discovered on 19 September 1973, by Dutch astronomersIngrid andCornelis van Houten at Leiden, andTom Gehrels thePalomar Observatory.[1] The asteroid has arotation period of 7.67 hours.[3] It was named after the former city district of Tokyo,Azabu.[1]
Azabu is a member of the dynamicalHilda group, located beyond the actual core region of the asteroid belt, and locked in a 3:2orbital 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 theHilda family (001), but an asteroid of thebackground population.[4]
This asteroid orbits the Sun in theouter 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 aneccentricity of 0.13 and aninclination of 3° with respect to theecliptic.[2] The body'sobservation arc begins with aprecovery taken at Palomar in April 1954, or 29 years prior to its official discovery observation.[1]
Despite being discovered during the secondPalomar–Leiden Trojan survey in 1973,Azabu has not received a provisionalsurvey designation starting with "T-2". This may be related to the swapped naming rights proposed byTom Gehrels(see below). The survey was a fruitful collaboration between the Palomar andLeiden observatories during the 1960s and 1970s. Gehrels used Palomar'sSamuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped thephotographic plates to Ingrid and Cornelis van Houten at Leiden Observatory whereastrometry was carried out. The trio are credited with the discovery ofseveral thousand asteroid discoveries.[10]
The asteroid has been characterized as anXL-type byPan-STARRS and in theSDSS-based taxonomy.[8][9] It is also characterized as a carbonaceousC-type asteroid in theSDSS-MFB (Masi Foglia Binzel) taxonomy.[3][b]
In April 2017, a rotationallightcurve ofAzabu was obtained fromphotometric observations byBrian Warner andRobert Stephens at theCenter for Solar System Studies in California. Lightcurve analysis gave a securerotation period of 7.670 hours with a brightness amplitude of 0.23magnitude (U=3-),[6][a] superseding a measurement of approximately 12 hours from the 1990s (U=1).[5]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Azabu measures 10.2 kilometers in diameter and its surface has analbedo between 0.32.[5] TheCollaborative 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 anabsolute magnitude of 12.1.[3]
Thisminor planet was named afterAzabu, a former district of the city of Tokyo, where theTokyo Astronomical Observatory was previously located.[1] The official naming citation was published by theMinor Planet Center on 16 December 1986 (M.P.C. 11442).[11]
Based on a proposal by the discovererTom Gehrels, the naming right for this asteroid were swapped with3291 Dunlap (discovered by Japanese astronomers), in order to create a quartet of sequentially named asteroids named afterLawrence Dunlap, Bob Sather, Ronald Raylor, and Carl Vesely (numbers 3291–3294).[12]
