167 Urda

167 Urda

A three-dimensional model of 167 Urda based on its light curve.
Discovery
Discovered by	C. H. F. Peters
Discovery site	Clinton, New York
Discovery date	August 28, 1876
Designations
MPC designation	167
Named after	Urd
Minor planet category	main belt (Koronis asteroid family)
Orbital characteristics
Epoch August 27, 2011
Aphelion	2.9477912 AU
Perihelion	2.7571486 AU
Semi-major axis	2.8524699 AU
Eccentricity	0.0334171
Orbital period	1759.6652178 d 4.28 a
Mean anomaly	34.23521°
Inclination	2.21112°
Longitude of ascending node	166.43581°
Argument of perihelion	128.43335°
Physical characteristics
Dimensions	39.94 km
Rotation period	13.07 h
Albedo	0.2230
Spectral type	S
Absolute magnitude (H)	9.24

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.

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. This S-type asteroid is a member of the Koronis family of asteroids that share similar orbital elements.

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.

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

External links

• 167 Urda at the JPL Small-Body Database

• Discovery · Orbit diagram · Urda#elem Orbital elements · Physical parameters