1991 Darwin, provisional designation 1967 JL, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 5 kilometers in diameter.

1991 Darwin
Discovered byC. U. Cesco
A. R. Klemola
Discovery siteEl Leoncito
(Yale–Columbia Southern Station) Félix Aguilar Obs.
Discovery date6 May 1967
(1991) Darwin
Named after
Charles Darwin
George Darwin[2]
1967 JL · 1954 UG
1971 SU2
main-belt · Flora[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc62.44 yr (22,807 days)
Aphelion2.7157 AU
Perihelion1.7829 AU
2.2493 AU
3.37 yr (1,232 days)
0° 17m 31.92s / day
Physical characteristics
Dimensions4.989±0.371 km[4][5]
5.02 km (taken)[3]
5.024 km[6]
5.84±1.26 km[7]
6.32±1.28 km[8]
4.7±0.2 h[9]
13.20±0.32[10] · 13.4[1][7] · 13.6[4][3] · 13.60±0.07[6][9] · 13.86[8]

It was discovered on 6 May 1967, by Argentine astronomers Carlos Cesco and Arnold Klemola at the El Leoncito's Yale–Columbia Southern Station of the Félix Aguilar Observatory in Argentina.[11] It was named for both George and Charles Darwin.[2]

Classification and orbitEdit

Darwin is a member of the Flora family, one of the largest groups of stony asteroids in the main-belt. It orbits the Sun in the inner main-belt at a distance of 1.8–2.7 AU once every 3 years and 4 months (1,232 days). Its orbit has an eccentricity of 0.21 and an inclination of 6° with respect to the ecliptic.[1]

It was first observed as 1954 UG at Goethe Link Observatory in 1954, extending the body's observation arc by 13 years prior to its official discovery observation at El Lenoncito.[11]

Physical characteristicsEdit

Darwin has been characterized as a common stony S-type asteroid based on its classification to the Flora family.[3]

Rotation periodEdit

In September 1991, a rotational lightcurve of Darwin was obtained from photometric observations by Polish astronomer Wiesław Wiśniewski. Lightcurve analysis gave a rotation period of 4.7 hours with a brightness amplitude of 0.08 magnitude (U=2).[9]

Diameter and albedoEdit

According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Darwin measures between 4.989 and 6.32 kilometers in diameter and its surface has an albedo between 0.16 and 0.28.[4][5][7][8]

The Collaborative Asteroid Lightcurve Link adopts Pravec's revised WISE data, that is, an albedo of 0.2541 and a diameter of 5.02 kilometers with an absolute magnitude of 13.6.[3][6]


This minor planet was named in memory of English naturalist Charles Darwin (1809–1882), the first to establish the theory of biological evolution. While on research in Argentina, he crossed the Andes relatively near to the Leoncito Astronomical Complex where the minor planet was discovered.[2]

The asteroid also honors George Darwin (1845–1912), his second son who was a noted astronomer for his pioneering application of detailed dynamical analyses to problems of cosmogony and geology. The Darwins are also honored by the lunar and Martian craters Darwin.[2] The official naming citation was published by the Minor Planet Center on 1 April 1980 (M.P.C. 5282).[12]


  1. ^ a b c d "JPL Small-Body Database Browser: 1991 Darwin (1967 JL)" (2017-03-30 last obs.). Jet Propulsion Laboratory. Retrieved 10 June 2017.
  2. ^ a b c d Schmadel, Lutz D. (2007). "(1991) Darwin". Dictionary of Minor Planet Names – (1991) Darwin. Springer Berlin Heidelberg. p. 161. doi:10.1007/978-3-540-29925-7_1992. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f "LCDB Data for (1991) Darwin". Asteroid Lightcurve Database (LCDB). Retrieved 8 December 2016.
  4. ^ 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.
  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. Retrieved 8 December 2016.
  6. ^ a b c d Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026. Retrieved 8 December 2016.
  7. ^ a b c d Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. Retrieved 10 June 2017.
  8. ^ a b c d Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T.; et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal. 152 (3): 12. arXiv:1606.08923. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63. Retrieved 10 June 2017.
  9. ^ a b c Wisniewski, W. Z.; Michalowski, T. M.; Harris, A. W.; McMillan, R. S. (March 1995). "Photoelectric Observations of 125 Asteroids". Abstracts of the Lunar and Planetary Science Conference. 26: 1511. Bibcode:1995LPI....26.1511W. Retrieved 8 December 2016.
  10. ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 8 December 2016.
  11. ^ a b "1991 Darwin (1967 JL)". Minor Planet Center. Retrieved 8 December 2016.
  12. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 8 December 2016.

External linksEdit