Deficit of primitive compositions in binary asteroids and pairs
Abstract
Context. Small binary asteroid systems and pairs are thought to form through fission induced by spin up via the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect. This process is expected to depend on their structural strength and therefore composition.
Aims: We aim to determine how taxonomic classes - used as a proxy for composition - are distributed amongst binary asteroids and asteroid pairs compared to the general population.
Methods: We compared the distribution of taxonomic classes of binary systems and pairs with that of a reference sample of asteroids. We built this sample by selecting asteroids in a way that reproduces the orbital and size distribution of the binaries and pairs. We did this in order to minimize potential biases between samples.
Results: A strong deficit of primitive compositions (C, B, P, D types) among binary asteroids and asteroid pairs is identified, as well as a strong excess of asteroids with mafic-silicate-rich surface compositions (S, Q, V, A types).
Conclusions: Amongst low-mass, rapidly rotating asteroids, those with mafic-silicate-rich compositions are more likely to form multiple asteroid systems than their primitive counterparts.
- Publication:
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Astronomy and Astrophysics
- Pub Date:
- April 2023
- DOI:
- 10.1051/0004-6361/202245538
- arXiv:
- arXiv:2302.02668
- Bibcode:
- 2023A&A...672A..48M
- Keywords:
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- minor planets;
- asteroids: general;
- methods: statistical;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 12 pages, 7 figures, last 5 pages are tables