1763 Williams

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1763 Williams
Discovery [1]
Discovered by Indiana University
(Indiana Asteroid Program)
Discovery site Goethe Link Obs.
Discovery date 13 October 1953
MPC designation (1763) Williams
Named after
Kenneth P. Williams[2]
(professor of mathematics at IU)
1953 TN2 · 1939 EO
1953 VJ · 1966 TN
main-belt · Flora[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 63.73 yr (23,276 days)
Aphelion 2.6340 AU
Perihelion 1.7436 AU
2.1888 AU
Eccentricity 0.2034
3.24 yr (1,183 days)
0° 18m 15.84s / day
Inclination 4.2352°
Physical characteristics
Dimensions 6.38±1.47 km[4]
6.982±0.183 km[5][6]
7.47 km (calculated)[3]
8 h[7]
36 h[a]
0.24 (assumed)[3]
12.6[6] · 12.68±0.26[8] · 12.80[1][3][4]

1763 Williams, provisional designation 1953 TN2, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 13 October 1953, by astronomers of the Indiana Asteroid Program at Goethe Link Observatory in Indiana, United States.[9] The asteroid was named after Kenneth P. Williams, professor of mathematics at Indiana University.[2]

Orbit and classification[edit]

Based on its osculating Keplerian orbital elements, Williams qualifies as a member of the Flora family (402), a giant asteroid family and the largest family of stony asteroids in the main-belt.[3] However, analysis using proper orbital elements in a hierarchical clustering method showed that Williams is a background asteroid, not belonging to any known family.[10]

The asteroid orbits the Sun in the inner main-belt at a distance of 1.7–2.6 AU once every 3 years and 3 months (1,183 days). Its orbit has an eccentricity of 0.20 and an inclination of 4° with respect to the ecliptic.[1]

The asteroid was first identified as 1939 EO at Nice Observatory in March 1939. The body's observation arc begins with its official discovery observation in October 1953.[9]

Physical characteristics[edit]

Williams is an assumed S-type asteroid.[3]

Rotation period[edit]

In October 2008, a rotational lightcurve of Williams was obtained from photometric observations by Petr Pravec at Ondřejov Observatory in the Czech Republic. Lightcurve analysis gave a rotation period of at least 36 hours with a brightness amplitude of more than 0.30 magnitude (U=2).[a][b] Another observation by Pierre Antonini gave a period of 8 hours (U=1+).[7]

Diameter and albedo[edit]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Williams measures 6.38 and 6.982 kilometers in diameter and its surface has an albedo of 0.32 and 0.3305, respectively.[4][5][6]

The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the Flora family's largest member and namesake – and calculates a diameter of 7.47 kilometers based on an absolute magnitude of 12.8.[3]


This minor planet was named in honor of Kenneth P. Williams (1887–1958), long-time professor of mathematics at Indiana University. He was known for his textbook, the calculation of the orbits of asteroids and comets, and his detailed analysis of the transits of Mercury from 1723 to 1927. He also wrote Lincoln Finds a General, a five volume book about the American Civil War.[2]

The name was proposed by Frank K. Edmondson, who initiated the Indiana Asteroid Program.[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 3143).[11]


  1. ^ a b Pravec (2008) web: rotation period of at least 36 hours with a brightness amplitude of greater than 0.30 mag. Quality Code of 2. Summary figures at Collaborative Asteroid Lightcurve Link (CALL)
  2. ^ Lightcurve plot for (1763) Williams with a period of 90 hours (P > 36 h and A > 0.3 mag). Summary figures at website of the Ondrejov Asteroid Photometry Project


  1. ^ a b c d "JPL Small-Body Database Browser: 1763 Williams (1953 TN2)" (2017-07-05 last obs.). Jet Propulsion Laboratory. Retrieved 6 September 2017.
  2. ^ a b c d Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1763) Williams. Springer Berlin Heidelberg. pp. 140–141. ISBN 978-3-540-00238-3. Retrieved 6 September 2017.
  3. ^ a b c d e f g h "LCDB Data for (1763) Williams". Asteroid Lightcurve Database (LCDB). Retrieved 6 September 2017.
  4. ^ 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 6 September 2017.
  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 6 September 2017.
  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" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 6 September 2017.
  7. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1763) Williams". Geneva Observatory. Retrieved 6 September 2017.
  8. ^ 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 6 September 2017.
  9. ^ a b "1763 Williams (1953 TN2)". Minor Planet Center. Retrieved 6 September 2017.
  10. ^ "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Archived from the original on 16 August 2017. Retrieved 6 September 2017.
  11. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 6 September 2017.

External links[edit]