167 Urda

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167 Urda
167Urda (Lightcurve Inversion).png
A three-dimensional model of 167 Urda based on its light curve.
Discovered by C. H. F. Peters
Discovery site Clinton, New York
Discovery date August 28, 1876
MPC designation 167
Named after
main belt (Koronis asteroid family)
Orbital characteristics[1]
Epoch August 27, 2011
Aphelion 2.9477912 AU
Perihelion 2.7571486 AU
2.8524699 AU
Eccentricity 0.0334171
1759.6652178 d
4.28 a
Inclination 2.21112 °
Physical characteristics
Dimensions 39.94 km
13.07 h
Albedo 0.2230
Spectral type

167 Urda is a main-belt asteroid that was discovered by German-American astronomer Christian Heinrich Friedrich Peters on August 28, 1876 in Clinton, New York and named after Urd, one of the Norns in Norse mythology. In 1905, Austrian astronomer Johann Palisa showed that the asteroid varied in brightness.[2]

Photometric observations of this asteroid at the Palmer Divide Observatory in Colorado Springs, Colorado during 2007–8 gave a light curve with a period of 13.06133 ± 0.00002 hours.[3] This S-type asteroid is a member of the Koronis family of asteroids that share similar orbital elements.[4]

In 2002, a diameter estimate of 37.93 ± 3.17 km was obtained from the Midcourse Space Experiment observations, with an albedo of 0.2523 ± 0.0448.[5]

A stellar occultation by Urda was observed from Japan on July 23, 2001.


  1. ^ Yeomans, Donald K., "167 Urda", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-30. 
  2. ^ Maddrill, James D. (December 1905), "Variable Asteroid (167) Urda", Publications of the Astronomical Society of the Pacific 17 (105): 190–192, Bibcode:2008MPBu...35..167W. 
  3. ^ Warner, Brian D. et al. (October 2008), "Shape and Spin Models for Four Asteroids", Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 35 (4): 167–171, Bibcode:2008MPBu...35..167W. 
  4. ^ Moore, Patrick; Rees, Robin, eds. (2011), Patrick Moore's Data Book of Astronomy (2nd ed.), Cambridge University Press, pp. 164–165. 
  5. ^ Tedesco, Edward F. et al. (July 2002), "The Midcourse Space Experiment Infrared Minor Planet Survey", The Astronomical Journal 124 (124): 583–591, Bibcode:2002AJ....124..583T, doi:10.1086/340960.