9936 Al-Biruni

9936 Al-Biruni
Orbit of Al-Biruni (blue) compared to the inner planets and Jupiter (outermost)
Discovery [1]
Discovered byE. W. Elst
V. Ivanova
Discovery siteRozhen Obs.
Discovery date8 August 1986
(9936) Al-Biruni
Named after
البيروني al-Bīrūnī
(Persian astronomer)[2]
1986 PN4 · 1981 UV12
main-belt · (outer) [3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc35.62 yr (13,009 days)
Aphelion3.6534 AU
Perihelion2.5107 AU
3.0820 AU
5.41 yr (1,976 days)
0° 10m 55.92s / day
Physical characteristics
Dimensions22.16 km (calculated)[3]
24.187±0.314 km[6]
27.81±1.61 km[7]
10.704±0.010 h[8]
0.057 (assumed)[3]
12.1[1] · 11.7[6][7] · 12.0[3]

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.[2]

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]


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.[3]


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.[2] 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.


  1. ^ a b c d "JPL Small-Body Database Browser: 9936 Al-Biruni (1986 PN4)" (2017-06-05 last obs.). Jet Propulsion Laboratory. Retrieved 22 June 2017.
  2. ^ a b c Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names – (9936) Al-Biruni. Springer Berlin Heidelberg. p. 712. ISBN 978-3-540-29925-7. Retrieved 13 May 2016.
  3. ^ a b c d e f "LCDB Data for (9936) Al-Biruni". Asteroid Lightcurve Database (LCDB). Retrieved 13 May 2016.
  4. ^ The McGraw-Hill Encyclopedia of World Biography (1973)
  5. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. S2CID 118745497. Retrieved 4 December 2016.
  6. ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. S2CID 118700974. Retrieved 13 May 2016.
  7. ^ a b c d Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. (online, AcuA catalog p. 153)
  8. ^ a b Clark, Maurice; Joyce, Brian (December 2002). "Asteroid lightcurve photometry from Goodsell Observatory (741)". The Minor Planet Bulletin. 30 (1): 4–7. Bibcode:2003MPBu...30....4C. ISSN 1052-8091. Retrieved 18 December 2015.
  9. ^ a b "9936 Al-Biruni (1986 PN4)". Minor Planet Center. Retrieved 13 May 2016.
  10. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 13 May 2016.

External links[]