Evidence for a source of H chondrites in the outer main asteroid belt
Abstract
Aims: In this paper we report near-infrared spectroscopic observations of one of the largest potentially hazardous asteroids, (214869)
Methods: The spectrum of (214869) 2007 PA8 was analysed using the positions of 1 μm and 2 μm bands and by curve-matching with RELAB meteorites spectra. Its dynamical evolution was investigated by means of a 200 000-year numerical integration in the past of 1275 clones followed to the source region.
Results: (214869) 2007 PA8 has a very young surface with a composition more akin to H chondrites than to any other type of ordinary chondrite. It arrived from the outer Main Belt in the near-Earth space via the 5:2 mean motion resonance with Jupiter by eccentricity pumping. Identification of its source region far from (6) Hebe raises the possibility of the existence of a second parent body of the H chondrites that has a radically different post-accretion history. Future spectroscopic surveys in the 5:2 resonance region will most likely discover other asteroids with an H chondrite composition.
- Publication:
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Astronomy and Astrophysics
- Pub Date:
- July 2014
- DOI:
- 10.1051/0004-6361/201423949
- Bibcode:
- 2014A&A...567L...7N
- Keywords:
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- minor planets;
- asteroids: general;
- techniques: spectroscopic;
- celestial mechanics;
- methods: numerical