Artigo
PECULIAR EUPHROSYNE
Registration in:
Astrophysical Journal. Bristol: Iop Publishing Ltd, v. 792, n. 1, 15 p., 2014.
0004-637X
10.1088/0004-637X/792/1/46
WOS:000341172100046
4750709016042276
Author
Carruba, V. [UNESP]
Aljbaae, S. [UNESP]
Souami, D.
Abstract
The asteroid (31) Euphrosyne is the largest body of its namesake family, and it contains more than 99% of the family mass. Among large asteroid families, the Euphrosyne group is peculiar because of its quite steep size-frequency distribution (SFD), significantly depleted in large-and medium-sized asteroids (8 < D < 12 km). The current steep SFD of the Euphrosyne family has been suggested to be the result of a grazing impact in which only the farthest, smallest members failed to accrete. The Euphrosyne family is, however, also very peculiar because of its dynamics: near its center it is crossed by the nu(6) = g - g(6) linear secular resonance, and it hosts the largest population (140 bodies) of asteroids in nu(6) antialigned librating states (or Tina-like asteroids) in the main belt. In this work we investigated the orbital evolution of newly obtained members of the dynamical family, with an emphasis on its interaction with the nu(6) resonance. Because of its unique resonant configuration, large-and medium-sized asteroids tend to migrate away from the family orbital region faster than small-sized objects, which were ejected farther away from the family center. As a consequence, the SFD of the Euphrosyne family becomes steeper in time with a growing depletion in the number of the largest family members. We estimate that the current SFD could be attained from a typical, initial SFD on timescales of 500 Myr, consistent with estimates of the family age obtained with other independent methods. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) National Aeronautics and Space Administration Planetary Science Division of the National Aeronautics and Space Administration Univ Estadual Paulista, UNESP, Grp Dinam Orbital & Planetol, BR-12516410 Guaratingueta, SP, Brazil Univ Namur, Dept Math, Namur Ctr Complex Syst, NAXYS, B-5000 Namur, Belgium Univ Paris 06, F-75005 Paris, France Univ Estadual Paulista, UNESP, Grp Dinam Orbital & Planetol, BR-12516410 Guaratingueta, SP, Brazil CNPq: 305453/2011-4 11/19863-3 13/15357-1 14/06762-2