4340 Dence, provisional designation 1986 JZ, is a background or Phocaea asteroid from the inner regions of the asteroid belt, approximately 8 kilometers (5 miles) in diameter. It was discovered on 4 May 1986, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California.^[1] The S-type asteroid has a rotation period of 7.5 hours.^[4] It was named after Canadian geologist Michael R. Dence.^[1]

Orbit and classification

Dence is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.^[3] Based on osculating Keplerian orbital elements, the asteroid has also been classified as a member of the stony Phocaea family (701).^[4] It orbits the Sun in the inner asteroid belt at a distance of 1.8–2.9 AU once every 3 years and 8 months (1,353 days; semi-major axis of 2.39 AU). Its orbit has an eccentricity of 0.23 and an inclination of 25° with respect to the ecliptic.^[2] The body's observation arc begins with a precovery taken at the Siding Spring Observatory in November 1979, more than six years prior to its official discovery observation at Palomar.^[1]

Physical characteristics

In the SMASS classification, Dence is a common, stony S-type asteroid.^[2][4]

Naming

This minor planet was named after Canadian geologist Michael R. Dence executive director of the Royal Society of Canada. He was a pioneer in the geologic investigation of ancient impact craters on the Canadian Shield (also see Sudbury Basin and Manicouagan Reservoir).^[1] The official naming citation was published by the Minor Planet Center on 30 January 1991 (M.P.C. 17656).^[10]

Notes

References

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• 4340 Dence at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 4340 Dence at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters