| Discovery[1] | |
|---|---|
| Discovered by | K. Endate K. Watanabe |
| Discovery site | Kitami Obs. |
| Discovery date | 15 February 1990 |
| Designations | |
| (5481) Kiuchi | |
Named after | Tsuruhiko Kiuchi (Japanese amateur astronomer)[2] |
| 1990 CH · 1970 SR | |
| main-belt · Vesta[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 46.14 yr (16,851 days) |
| Aphelion | 2.4858AU |
| Perihelion | 2.1936 AU |
| 2.3397 AU | |
| Eccentricity | 0.0624 |
| 3.58yr (1,307 days) | |
| 194.33° | |
| 0° 16m 31.44s / day | |
| Inclination | 5.9569° |
| 326.10° | |
| 250.69° | |
| Knownsatellites | 1(Ds/Dp 0.33,P: 20.90 h)[4] |
| Physical characteristics | |
| 3.86 km(calculated)[5] | |
| 3.6196±0.0002 h[4][6] | |
| 0.40(assumed)[5] | |
| V[5][7] | |
| 12.98±0.1(R)[4] · 13.4[1] · 13.676±0.062[5][8] · 13.73±0.29[7] | |
5481 Kiuchi, provisional designation1990 CH, is a brightbinary[4] Vestianasteroid from the inner regions of theasteroid belt, approximately 4 kilometers (2.5 miles) in diameter. It was discovered on 15 February 1990, by Japanese astronomersKin Endate andKazuro Watanabe atKitami Observatory in Hokkaidō, Japan, and named after their colleagueTsuruhiko Kiuchi.[2][9] TheV-type asteroid has arotation period of 3.6 hours.[5]
Kiuchi is a bright core member of theVesta family,[3] one of the main-belt's largest families. It orbits the Sun in theinner main-belt at a distance of 2.2–2.5 AU once every 3 years and 7 months (1,307 days). Its orbit has aneccentricity of 0.06 and aninclination of 6° with respect to theecliptic.[1] It was first identified as1970 SR atCrimea–Nauchnij in 1970, extending the body'sobservation arc by 20 years prior to its official discovery observation at Kitami.[9]
Thisminor planet was named in honor of Japanese amateur astronomer and discoverer ofcomets, Tsuruhiko Kiuchi (born 1954), who is known for the rediscovery of the periodic PerseidComet Swift–Tuttle, a previouslylost comet (also see naming citations for5035 Swift and5036 Tuttle). Based on a prediction byBrian Marsden, Kiuchi made this rediscovery in 1992, using only binoculars.[2] The approved naming citation was published by theMinor Planet Center on 1 September 1993 (M.P.C. 22510).[10]
In March 2008, alightcurve ofKiuchi was obtained from photometric observations by astronomersPeter Kušnirák andPetr Pravec atOndřejov Observatory in the Czech Republic, by Julian Oey at Leura Observatory, Australia, byRobert Stephens at Goat Mountain, California, by Mark Husárik atSkalnaté pleso Observatory, Slovakia, and byJudit Györgyey Ries atMcDonald Observatory, Texas.
These photometric observations revealed, thatKiuchi is a synchronousbinary asteroid with aminor-planet moon orbiting it every 20.90 hours based on mutual eclipsing and occultation events. The satellite's diameter is about a third of that ofKiuchi, which translates into 1.3 kilometers (secondary-to-primary mean-diameter ratio of0.33±0.02).[4]
According to the surveys carried out byPanSTARRS,Kiuchi is a brightV-type asteroid.[7] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.40 and calculates a diameter of 3.86 kilometers, using anabsolute magnitude of 13.676 from Petr Pravec's revisedWISE data.[5]
Kiuchi itself has arotation period of3.6196±0.0002 hours with a small brightness variation of 0.1magnitude, indicating a nearly spheroidal shape (U=n.a.).[4] Photometric follow-up observations by Petr Pravec confirmed the results in 2013 and 2016, giving a period of 3.6198 and 3.6196 hours with an amplitude of 0.08 and 0.1 magnitude, and an orbital period for the satellite of 20.9 and 20.9062 hours, respectively (U=3/n.a.).[6][a]
