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Abstract The Gaia mission has detected many white dwarfs (WDs) in binary and triple configurations, and while observations suggest that triple-stellar systems are common in our Galaxy, not much attention was devoted to WDs in triples. For stability reasons, these triples must have hierarchical configurations, i.e., two stars are on a tight orbit (the inner binary), with the third companion on a wider orbit about the inner binary. In such a system, the two orbits torque each other via the eccentric Kozai–Lidov mechanism, which can alter the orbital configuration of the inner binary. We simulate thousands of triple-stellar systems for over 10 Gyr, tracking gravitational interactions, tides, general relativity, and stellar evolution up to their WD fate. As demonstrated here, three-body dynamics coupled with stellar evolution is a critical channel to form tight WD binaries or merge a WD binary. Among these triples, we explore their manifestations as cataclysmic variables, Type Ia supernovae, and gravitational-wave events. The simulated systems are then compared to a sample of WD triples selected from the Gaia catalog. We find that including the effect of mass-loss-induced kicks is crucial for producing a distribution of the inner binary–tertiary separations that is consistent with Gaia observations. Lastly, we leverage this consistency to estimate that, at minimum, 30% of solar-type stars in the local 200 pc were born in triples.
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Formation of the inner Oort cloud in the presence of an early solar binary
ABSTRACT Consistent with the notion that most Sun-like stars form in multistellar systems, this study explores the impact of a temporarily bound stellar binary companion on the early dynamical evolution of the Solar system. Using N-body simulations, we illustrate how such a companion markedly enhances the trapping of scattered bodies on inner Oort cloud-like orbits, with perihelion distances exceeding $$q \gt 40$$ au. We further find that the orbital geometry of the Sun-binary system plays a central role in regulating the efficiency of small-body implantation on to high-perihelion orbits, and demonstrate that this process is driven by the von Zeipel–Kozai–Lidov mechanism. Incorporating the transiency of stellar clusters and the eventual Sun-binary pair dissociation due to passing stars, we show how the binary can be stripped away by an approximately solar-mass ejector star, with only a modest impact on the generated inner Oort cloud population. Collectively, our results highlight a previously underappreciated process that could have contributed to the formation of the inner Oort cloud.
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- Award ID(s):
- 2109276
- PAR ID:
- 10521076
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Monthly Notices of the Royal Astronomical Society: Letters
- Volume:
- 533
- Issue:
- 1
- ISSN:
- 1745-3925
- Format(s):
- Medium: X Size: p. L43-L48
- Size(s):
- p. L43-L48
- Sponsoring Org:
- National Science Foundation
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