16765 Agnesi

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
16765 Agnesi
Discovery [1]
Discovered by P. G. Comba
Discovery site Prescott Obs.
Discovery date 16 October 1996
MPC designation (16765) Agnesi
Named after
Maria Agnesi
(Italian mathematician)[2]
1996 UA
main-belt · Eunomia[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 19.88 yr (7,261 days)
Aphelion 2.9139 AU
Perihelion 2.3361 AU
2.6250 AU
Eccentricity 0.1101
4.25 yr (1,553 days)
0° 13m 54.12s / day
Inclination 12.266°
Physical characteristics
Dimensions 3.84 km (calculated)[3]
4.132±0.247 km[4][5]
7.5458±0.0034 h[6]
0.21 (assumed)[3]
13.9[1][4] · 13.30±0.00[7] · 13.943±0.004 (R)[6] · 14.39[3]

16765 Agnesi, provisional designation 1996 UA, is a stony Eunomia asteroid from the middle region of the asteroid belt, approximately 4 kilometers in diameter. It was discovered on 16 October 1996, by Italian-American amateur astronomer Paul Comba at his private Prescott Observatory in Arizona, United States.[8] The asteroid was named after Italian mathematician Maria Gaetana Agnesi.[2]

Orbit and classification[edit]

Agnesi is a member of the Eunomia family, a large group of S-type asteroids and the most prominent family in the central main-belt. It orbits the Sun at a distance of 2.3–2.9 AU once every 4 years and 3 months (1,553 days). Its orbit has an eccentricity of 0.11 and an inclination of 12° with respect to the ecliptic.[1] It was first observed by Haleakala–NEAT/GEODSS (566), extending the asteroid's observation arc by 32 days prior to its official discovery observation.[8]

Physical characteristics[edit]

Diameter and albedo[edit]

According to the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, Agnesi measures 4.1 kilometers in diameter and its surface has an albedo of 0.28,[4] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.21 – derived from 15 Eunomia, the family's largest member and namesake – and calculates a diameter of 3.8 kilometers.[3]


A rotational lightcurve of Agnesi was obtained from photometric observations taken by astronomers at the Palomar Transient Factory in September 2013. Lightcurve analysis gave a rotation period of 7.5458 hours with a brightness variation of 0.31 magnitude (U=2).[6]


This minor planet was named in honor of Italian Maria Gaetana Agnesi (1718–1799), who was the first Western woman to write a widely translated mathematics handbook and the first woman appointed to a professorship at a university in 1750.[2] The official naming citation was published by the Minor Planet Center on 9 January 2001 (M.P.C. 41941).[9]


  1. ^ a b c d "JPL Small-Body Database Browser: 16765 Agnesi (1996 UA)" (2016-08-01 last obs.). Jet Propulsion Laboratory. Retrieved 26 June 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (16765) Agnesi. Springer Berlin Heidelberg. p. 840. ISBN 978-3-540-00238-3. Retrieved 2 May 2016. 
  3. ^ a b c d e f "LCDB Data for (16765) Agnesi". Asteroid Lightcurve Database (LCDB). Retrieved 2 May 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:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 2 May 2016. 
  5. ^ a b 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:1109.4096Freely accessible. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 3 December 2016. 
  6. ^ a b c Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041Freely accessible. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 2 May 2016. 
  7. ^ 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:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 2 May 2016. 
  8. ^ a b "16765 Agnesi (1996 UA)". Minor Planet Center. Retrieved 2 May 2016. 
  9. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 2 May 2016. 

External links[edit]