9936 Al-Biruni, provisional designation 1986 PN₄, is a carbonaceous asteroid from the outer region of the asteroid belt, approximately 24 kilometers in diameter. It was discovered on 8 August 1986, by Belgian and Bulgarian astronomers Eric Elst and Violeta Ivanova at the Rozhen Observatory, located in Bulgaria's Smolyan province near the border to Greece.[9] It was named for Persian medieval scholar Al-Biruni.[3]

9936 Al-Biruni

Orbit of Al-Biruni (blue) compared to the inner planets and Jupiter (outermost)
Discovery [1]
Discovered by	E. W. Elst V. Ivanova
Discovery site	Rozhen Obs.
Discovery date	8 August 1986
Designations
MPC designation	(9936) Al-Biruni
Pronunciation	/ælbɪˈruːni/[2]
Named after	البيروني al-Bīrūnī (Persian astronomer)[3]
Alternative designations	1986 PN4 · 1981 UV12
Minor planet category	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	3.6534 AU
Perihelion	2.5107 AU
Semi-major axis	3.0820 AU
Eccentricity	0.1854
Orbital period (sidereal)	5.41 yr (1,976 days)
Mean anomaly	279.59°
Mean motion	0° 10m 55.92s / day
Inclination	15.404°
Longitude of ascending node	310.41°
Argument of perihelion	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]
Synodic rotation period	10.704±0.010 h[8]
Geometric albedo	0.048±0.006[7] 0.057 (assumed)[4] 0.0632±0.0151[6] 0.065±0.012[5]
Spectral type	C [4]
Absolute magnitude (H)	12.1[1] · 11.7[6][7] · 12.0[4]

Orbit and classification

Al-Biruni orbits the Sun in the outer main-belt at a distance of 2.5–3.7 AU once every 5 years and 5 months (1,976 days). Its orbit has an eccentricity of 0.19 and an inclination of 15° with respect to the ecliptic.[1] It was first identified as 1981 UV₁₂ at Crimea-Nauchnij in 1981, extending the body's observation arc by 5 years prior to its official discovery at Rozhen.[9]

Lightcurve

A rotational lightcurve of Al-Biruni was obtained from photometric observations made at the U.S. Goodsell Observatory (741), Minnesota, in August 2002. The lightcurve gave a rotation period of 10.704±0.010 hours with a brightness amplitude of 0.14 in magnitude (U=2)[8]

Diameter and albedo

According to the space-based surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Al-Biruni measures between 23.9 and 27.8 kilometers in diameter, and its surface has a corresponding albedo of 0.048 to 0.065.[5][6][7] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 22.2 kilometers with an absolute magnitude of 12.0.[4]

Naming

The minor planet was named after the Persian scholar and polymath Al-Biruni (973–1048). Regarded as the founder of Indology and the father of geodesy, 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 the Minor Planet Center on 26 September 2007 (M.P.C. 60728).[10] The lunar crater Al-Biruni is also named in his honour.

References

External links

• Rozhen Observatory, Smolyan, Bulgaria
• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (5001)-(10000) – Minor Planet Center
• 9936 Al-Biruni at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 9936 Al-Biruni at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters