Astronomy:Koronis family
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The Koronis or Koronian family (FIN: 605), also known as the Lacrimosa family,[1]: 16 is a very large asteroid family of stony asteroids, located in the outer region of the asteroid belt. They are thought to have been formed at least two billion years ago in a catastrophic collision between two larger bodies. The family is named after its lowest-numbered member 158 Koronis, and the largest known member (208 Lacrimosa) is about 41 km (25 mi) in diameter. Koronis family members travel in independent heliocentric orbits which share similar semimajor axes, eccentricities, and inclinations, but the asteroids themselves are not physically clustered in space. The spin poles of several of the large members do appear to be aligned in space.[2] The family has at least 5949 members.[1]
This family has two subfamilies. The Karin family (FIN: 610) was formed remarkably recently in a catastrophic collision (destroying the parent body), with an estimated age of 5.72 million years. The Koronis(2) family (FIN: 621) with 246 members is the other.[1] It formed 15 million years ago by a non-catastrophic collision with 158 Koronis.[3]
On August 28, 1993, the Galileo spacecraft visited a member of this family, 243 Ida. A photo of Ida (and its tiny moon Dactyl) is part of the composite image at right (numbered 243).
Large members
| Asteroid | Median diameter |
Semi-major axis | Orbital inclination |
Orbital eccentricity |
Discovered | Refs | |
|---|---|---|---|---|---|---|---|
| 158 | Koronis | 35.4 km | 2.867 AU | 1.00° | 0.057 | 1876 | JPL · MPC |
| 167 | Urda | 39.9 km | 2.855 AU | 2.21° | 0.035 | 1876 | JPL · MPC |
| 208 | Lacrimosa | 41.0 km | 2.895 AU | 1.751° | 0.015 | 1879 | JPL · MPC |
| 243 | Ida | 31.3 km | 2.861 AU | 1.138° | 0.046 | 1884 | JPL · MPC |
| 263 | Dresda | 23.0 km | 2.886 AU | 1.314° | 0.079 | 1886 | JPL · MPC |
| 277 | Elvira | 27.0 km | 2.887 AU | 1.156° | 0.089 | 1888 | JPL · MPC |
| 311 | Claudia | 24.0 km | 2.897 AU | 3.225° | 0.008 | 1891 | JPL · MPC |
| 321 | Florentina | 27.0 km | 2.886 AU | 2.594° | 0.043 | 1891 | JPL · MPC |
| 534 | Nassovia | 32.3 km | 2.884 AU | 3.277° | 0.057 | 1904 | JPL · MPC |
| 720 | Bohlinia | 33.7 km | 2.888 AU | 2.359° | 0.014 | 1911 | JPL · MPC |
| 1223 | Neckar | 22.8 km | 2.869 AU | 2.55052º | 0.061 | 1931 | JPL · MPC |
References
- ↑ 1.0 1.1 1.2 Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV. pp. 297–321. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131. Bibcode: 2015aste.book..297N.
- ↑ "Fresh Spin on Solar Powered Asteroids", Space.com, 10 September 2003
- ↑ Molnar, Lawrence A.; Haegert, M. J. (September 2009). "Details of Recent Collisions of Asteroids 832 Karin and 158 Koronis". American Astronomical Society 41: 27.05. Bibcode: 2009DPS....41.2705M.
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