![]() Orbit ofAl-Biruni (blue) compared to theinner planets andJupiter (outermost) | |
| Discovery[1] | |
|---|---|
| Discovered by | E. W. Elst V. Ivanova |
| Discovery site | Rozhen Obs. |
| Discovery date | 8 August 1986 |
| Designations | |
| (9936) Al-Biruni | |
| Pronunciation | /ælbɪˈruːni/[2] |
Named after | البيرونيal-Bīrūnī (Persian astronomer)[3] |
| 1986 PN4 · 1981 UV12 | |
| main-belt · (outer)[4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 35.62 yr (13,009 days) |
| Aphelion | 3.6534AU |
| Perihelion | 2.5107 AU |
| 3.0820 AU | |
| Eccentricity | 0.1854 |
| 5.41yr (1,976 days) | |
| 279.59° | |
| 0° 10m 55.92s / day | |
| Inclination | 15.404° |
| 310.41° | |
| 13.774° | |
| Physical characteristics | |
| Dimensions | 22.16 km(calculated)[4] 23.890±0.170[5] 24.187±0.314 km[6] 27.81±1.61 km[7] |
| 10.704±0.010h[8] | |
| 0.048±0.006[7] 0.057(assumed)[4] 0.0632±0.0151[6] 0.065±0.012[5] | |
| C[4] | |
| 12.1[1] · 11.7[6][7] · 12.0[4] | |
9936 Al-Biruni, provisional designation1986 PN4, is a carbonaceousasteroid from the outer region of theasteroid belt, approximately 24 kilometers in diameter. It was discovered on 8 August 1986, by Belgian and Bulgarian astronomersEric Elst andVioleta Ivanova at theRozhen Observatory, located in Bulgaria's Smolyan province near the border to Greece.[9] It was named for Persian medieval scholarAl-Biruni.[3]
Al-Biruni orbits the Sun in theouter main-belt at a distance of 2.5–3.7 AU once every 5 years and 5 months (1,976 days). Its orbit has aneccentricity of 0.19 and aninclination of 15° with respect to theecliptic.[1] It was first identified as1981 UV12 atCrimea-Nauchnij in 1981, extending the body'sobservation arc by 5 years prior to its official discovery at Rozhen.[9]
A rotationallightcurve ofAl-Biruni was obtained from photometric observations made at the U.S.Goodsell Observatory (741), Minnesota, in August 2002. The lightcurve gave arotation period of10.704±0.010 hours with a brightness amplitude of 0.14 inmagnitude (U=2)[8]
According to the space-based surveys carried out by the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Al-Biruni measures between 23.9 and 27.8 kilometers in diameter, and its surface has a correspondingalbedo of 0.048 to 0.065.[5][6][7] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo forcarbonaceous asteroids of 0.057 and calculates a diameter of 22.2 kilometers with anabsolute magnitude of 12.0.[4]
Theminor planet was named after the Persian scholar and polymathAl-Biruni (973–1048). Regarded as the founder ofIndology and the father ofgeodesy, he made important contributions to anthropology, mathematics and astronomy. In particular, he is known for developing a method for the summation of series, for solving algebraic equations, and for the triangulation of distances on Earth's surface.[3] The official naming citation was published by theMinor Planet Center on 26 September 2007 (M.P.C. 60728).[10] The lunar craterAl-Biruni is also named in his honour.