Is there an exoplanet in the solar system?
Open accessAbstract
We investigate the prospects for the capture of the proposed Planet 9 from other stars in the Sun's birth cluster. Any capture scenario must satisfy three conditions: the encounter must be more distant than ∼150 au to avoid perturbing the Kuiper belt; the other star must have a wide-orbit planet (a ≳ 100 au); the planet must be captured on to an appropriate orbit to sculpt the orbital distribution of wide-orbit Solar system bodies. Here we use N-body simulations to show that these criteria may be simultaneously satisfied. In a few per cent of slow close encounters in a cluster, bodies are captured on to heliocentric, Planet 9-like orbits. During the ∼100 Myr cluster phase, many stars are likely to host planets on highly eccentric orbits with apastron distances beyond 100 au if Neptune-sized planets are common and susceptible to planet–planet scattering. While the existence of Planet 9 remains unproven, we consider capture from one of the Sun's young brethren a plausible route to explain such an object's orbit. Capture appears to predict a large population of trans-Neptunian objects (TNOs) whose orbits are aligned with the captured planet, and we propose that different formation mechanisms will be distinguishable based on their imprint on the distribution of TNOs.
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For conditions expected in the solar birth cluster, the probability for successful capture of Planet Nine is of order a few percent, both for freely floating planets and for planets captured from other planetary systems.
“For the conditions expected in the solar birth cluster, the probability for successful capture is of order a few percent, both for freely floating planets (Li and Adams, 2016), and for planets captured from other planetary systems (Mustill et al., 2016).”
From The planet nine hypothesis (2019) · cites this paper as Mustill et al., 2016
Cites
A hybrid symplectic integrator that permits close encounters between massive bodies
Chambers, J. E. (1999) · Monthly Notices of the Royal Astronomical Society · doi:10.1046/j.1365-8711.1999.02379.x · Cited by 1,820 · see citing works
Giant Planet Formation by Gravitational Instability
Boss, A. P. (1997) · Science · doi:10.1126/science.276.5320.1836 · Cited by 1,124 · cited 1× · see citing works
“While in situ formation of super-Jovian planets may be possible via gravitational instability (Boss 1997; Kratter & Lodato 2016), this could not lead to the formation of Neptune-or super Earth-mass planets.”
The Birth Environment of the Solar System
Adams, F. C. (2010) · Annual Review of Astronomy and Astrophysics · doi:10.1146/annurev-astro-081309-130830 · Cited by 464 · see citing works
Evidence for a Distant Giant Planet in the Solar System
Batygin, K., & Brown, M. E. (2016) · The Astronomical Journal · doi:10.3847/0004-6256/151/2/22 · Cited by 432 · cited 2× · see citing works
“Batygin & Brown (2016) show that families of aligned and anti-aligned particles can exist under the influence of Planet 9, and in our integration a strong concentration of particles in orbits aligned with the planet is evident, together with a small number in an anti-aligned con-figuration.”
A Sedna-like body with a perihelion of 80 astronomical units
Trujillo, C. A., & Sheppard, S. S. (2014) · Nature · doi:10.1038/nature13156 · Cited by 303 · see citing works
Debris disks as signposts of terrestrial planet formation
Raymond, S. N., Armitage, P. J., Moro-Martín, A., Booth, M., Wyatt, M. C., Armstrong, J. C., Mandell, A. M., Selsis, F., & West, A. A. (2011) · Astronomy & Astrophysics · doi:10.1051/0004-6361/201116456 · Cited by 194 · see citing works
Self-citationMorbidelli, A., & Levison, H. F. (2004) · The Astronomical Journal · doi:10.1086/424617 · Cited by 193 · cited 1× · see citing works
“…can be transferred between stars in the slow ( ∼ 1kms − 1 ) close encounters typical in open clusters (Clarke & Pringle 1993; Kenyon & Bromley 2004; Morbidelli & Levison 2004; Pfalzner et al. 2005; Levison et al. 2010; Malmberg, Davies & Heggie 2011; Belbruno et al. 2012; J´ılkov´a et al.…”
Observational constraints on the orbit and location of Planet Nine in the outer solar system
Brown, M. E., & Batygin, K. (2016) · The Astrophysical Journal Letters · doi:10.3847/2041-8205/824/2/l23 · Cited by 112 · cited 6× · see citing works
“For each integration, we count the number of particles captured on to bound orbits around the Sun (imposing a cut-off of a = 5000 au to reject particles which spuriously remain bound after removal of the original host), as well as the number captured on to Novenito orbits of Brown & Batygin (2016).”
InfluentialINTERACTION CROSS SECTIONS AND SURVIVAL RATES FOR PROPOSED SOLAR SYSTEM MEMBER PLANET NINE
Li, G., & Adams, F. C. (2016) · The Astrophysical Journal Letters · doi:10.3847/2041-8205/823/1/l3 · Cited by 60 · see citing works
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Batygin, K., Adams, F. C., Brown, M. E., & Becker, J. C. (2019) · Physics Reports · doi:10.1016/j.physrep.2019.01.009 · Cited by 181 · see citing works
“This P9 capture scenario has been recently considered by a number of authors (Li and Adams, 2016; Mustill et al., 2016; Parker et al., 2017).”
BackgroundNew Extreme Trans-Neptunian Objects: Toward a Super-Earth in the Outer Solar System
Sheppard, S. S., & Trujillo, C. (2016) · The Astronomical Journal · doi:10.3847/1538-3881/152/6/221 · Cited by 92 · see citing works
Consequences of a Distant Massive Planet on the Large Semimajor Axis Trans-Neptunian Objects
Shankman, C., Kavelaars, J. J., Lawler, S. M., Gladman, B. J., & Bannister, M. T. (2017) · The Astronomical Journal · doi:10.3847/1538-3881/153/2/63 · Cited by 42 · see citing works
THE HUNT FOR PLANET NINE: ATMOSPHERE, SPECTRA, EVOLUTION, AND DETECTABILITY
Fortney, J. J., Marley, M. S., Laughlin, G., Nettelmann, N., Morley, C. V., Lupu, R. E., Visscher, C., Jeremic, P., Khadder, W. G., & Hargrave, M. (2016) · The Astrophysical Journal Letters · doi:10.3847/2041-8205/824/2/l25 · Cited by 36 · see citing works
- Authors
- Mustill, A. J., Raymond, S. N., & Davies, M. B.
- Affiliations
- Lund University (SE)
- Centre National de la Recherche Scientifique (FR)
- University of Cape Town (ZA)
- Venue
- Monthly Notices of the Royal Astronomical Society: Letters
- Publisher
- Oxford University Press (OUP)
- Published
- 2016-04
- Volume
- 460
- Issue
- 1
- Pages
- L109-L113
- ISSN
- 1745-3925 (ISSN-L)
- 1745-3933
- OpenAlex
- W2311611161
- Cited by
- 52
- References
- 9
- Citations by year
- 2026: 1 · 2025: 1 · 2023: 5 · 2022: 6 · 2021: 3 · 2020: 7 · 2019: 7 · 2018: 7 · 2017: 7 · 2016: 8
- FWCI
- 4.62
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Monthly Notices of the Royal Astronomical Society Letters (publishedVersion)
- arXiv (Cornell University) (acceptedVersion)
- HAL (submittedVersion, cc-by)
- Lund University Publications (Lund University) (submittedVersion)
- HighWire Press Open Archive (submittedVersion)
- Oskar-Bordeaux (Universite de Bordeaux) (submittedVersion)
- arXiv (Cornell University)
- Funders
- Agence Nationale de la Recherche (ANR-13-BS05-0003)
- Knut och Alice Wallenbergs Stiftelse
- Topics
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Astro and Planetary Science
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Stellar, planetary, and galactic studies
- Physical Sciences › Engineering › Aerospace Engineering › Space Satellite Systems and Control
- Keywords
- Planet Nine, stellar capture, wide-orbit planets, trans-Neptunian objects, Kuiper belt, planet-planet scattering, orbital distribution, N-body simulations, orbital alignment, solar system formation
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