Jump to content

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

[edit]
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]
Name Abs. Mag Size (km) proper
a
(AU)
proper
e
proper
i
153 Hilda 7.8 171 3.9653 0.174 8.917
1212 Francette 9.6 76 3.9674 0.230 7.237
1746 Brouwer 10.0 63 3.9631 0.141 9.251
1529 Oterma 10.0 56 3.9643 0.154 7.870
3134 Kostinsky 10.5 50 3.9658 0.184 8.966
1038 Tuckia 10.7 58 3.9648 0.164 8.239
3990 Heimdal 11.0 36 3.9651 0.168 9.641
4317 Garibaldi 11.1 39 3.9670 0.213 9.165
3571 Milanstefanik 11.3 35 3.9620 0.127 9.210
3561 Devine 11.3 33 3.9623 0.133 8.581

References

[edit]
  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. ^ a b 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.