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Hilda family

From Wikipedia, the free encyclopedia

The Hilda family (001[1]) is an ancient collisional asteroid family of at least 409 known asteroids,[2] named for its largest member, the 170-kilometre (110 mi)-across asteroid 153 Hilda. It lies within the larger dynamical group of Hilda asteroids, a group of asteroids in the 3:2 orbital resonance with Jupiter. All members of the family are dark P-type asteroids with albedos of around 0.06. Another asteroid family in the Hilda dynamical group is the Schubart family, named for its largest member, 1911 Schubart.

An asteroid family is a group of physically related asteroids usually created by a collision with an original larger asteroid, with the fragments continuing on similar orbits to the original. This is distinct from a dynamical group in that the members of a dynamical group only share similar orbits because of gravitational interactions with planets, which concentrate asteroids in a particular orbital range. Members of the Hilda family are both part of the wider Hilda dynamical group, and fragments of 153 Hilda. The family is considered a non-catastrophic asteroid family because 153 Hilda, its largest member, makes up nearly 3/4 of the family's total mass, rather than simply being the largest of a number of fragments each making up a small fraction of the original destroyed asteroid.[3]

The family is believed to be one of the oldest collisional families ever discovered, with an estimated age of likely 4 billion years.[4][5] Models based on the modern Solar System indicate it being very unlikely for an asteroid as large as 153 Hilda to suffer a collision large enough to create its family, even over the course of billions of years of encounters with other asteroids, leading to a 2011 study to propose that the family-creating impact event happened during the Late Heavy Bombardment, when impact rates in the Solar System were briefly much higher.[6]

Large members

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153 Hilda1212 Francette1746 Brouwer1529 Oterma3134 Kostinsky1038 Tuckia3990 Heimdal4317 Garibaldi3571 Milanstefanik3561 DevineHilda family
Mass distribution of the Hilda family (assuming similar densities)
The 10 brightest Hilda family members[2]
NameAbs. MagSize (km)proper
a
(AU)
proper
e
proper
i
153 Hilda7.81713.96530.1748.917
1212 Francette9.6763.96740.2307.237
1746 Brouwer10.0633.96310.1419.251
1529 Oterma10.0563.96430.1547.870
3134 Kostinsky10.5503.96580.1848.966
1038 Tuckia10.7583.96480.1648.239
3990 Heimdal11.0363.96510.1689.641
4317 Garibaldi11.1393.96700.2139.165
3571 Milanstefanik11.3353.96200.1279.210
3561 Devine11.3333.96230.1338.581

References

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  1. Nesvorny, D.; Broz, M.; Carruba, V. (2015). Identification and Dynamical Properties of Asteroid Families. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 978-0-8165-3213-1. {{cite book}}: |journal= ignored (help)
  2. 1 2 Nesvorný, David (14 August 2020). "Nesvorny HCM Asteroid Families | PDS SBN Asteroid/Dust Subnode". NASA Planetary Data System. doi:10.26033/6cg5-pt13.
  3. Holsapple, K.A.; Housen, K.R. (December 2019). "The catastrophic disruptions of asteroids: History, features, new constraints and interpretations". Planetary and Space Science. 179 104724. Bibcode:2019P&SS..17904724H. doi:10.1016/j.pss.2019.104724.
  4. Brož, M.; Vokrouhlický, D. (21 October 2008). "Asteroid families in the first-order resonances with Jupiter". Monthly Notices of the Royal Astronomical Society. 390 (2): 715–732. arXiv:1104.4004. Bibcode:2008MNRAS.390..715B. doi:10.1111/j.1365-2966.2008.13764.x.
  5. "Asteroid Family Ages". AstDyS. Retrieved 28 July 2024.
  6. Brož, M.; Vokrouhlický, D.; Morbidelli, A.; Nesvorný, D.; Bottke, W. F. (2 May 2011). "Did the Hilda collisional family form during the late heavy bombardment?". Monthly Notices of the Royal Astronomical Society. 414 (3): 2716–2727. arXiv:1109.1114. Bibcode:2011MNRAS.414.2716B. doi:10.1111/j.1365-2966.2011.18587.x.