Fly-by encounters between two planetary systems I: Solar system analogues
Li, Daohai LU
; Mustill, Alexander J.
LU
and Davies, Melvyn B.
LU
(2019)
In Monthly Notices of the Royal Astronomical Society
488(1).
p.1366-1376
- Abstract
- Stars formed in clusters can encounter other stars at close distances. In typical open clusters in the Solar neighbourhood containing hundreds or thousands of member stars, 10-20 per cent of Solar-mass member stars are expected to encounter another star at distances closer than 100 au. These close encounters strongly perturb the planetary systems, directly causing ejection of planets or their capture by the intruding star, as well as exciting the orbits. Using extensive N-body simulations, we study such fly-by encounters between two Solar system analogues, each with four giant planets from Jupiter to Neptune. We quantify the rates of loss and capture immediately after the encounter, e.g. the Neptune analogue is lost in one in four... (More)
- Stars formed in clusters can encounter other stars at close distances. In typical open clusters in the Solar neighbourhood containing hundreds or thousands of member stars, 10-20 per cent of Solar-mass member stars are expected to encounter another star at distances closer than 100 au. These close encounters strongly perturb the planetary systems, directly causing ejection of planets or their capture by the intruding star, as well as exciting the orbits. Using extensive N-body simulations, we study such fly-by encounters between two Solar system analogues, each with four giant planets from Jupiter to Neptune. We quantify the rates of loss and capture immediately after the encounter, e.g. the Neptune analogue is lost in one in four encounters within 100 au, and captured by the flying-by star in 1 in 12 encounters. We then perform long-term (up to 1 Gyr) simulations investigating the ensuing post-encounter evolution. We show that large numbers of planets are removed from systems due to planet-planet interactions and that captured planets further enhance the system instability. While encounters can initially leave a planetary system containing more planets by inserting additional ones, the long-term instability causes a net reduction in planet number. A captured planet ends up on a retrograde orbit in half of the runs in which it survives for 1Gyr; also, a planet bound to its original host star but flipped during the encounter may survive. Thus, encounters between planetary systems are a channel to create counter-rotating planets, This would happen in around 1 per cent of systems, and such planets are potentially detectable through astrometry or direct imaging. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/94170fbc-12b3-4c6e-9d9b-c82504fe343e
- author
- Li, Daohai
LU
; Mustill, Alexander J.
LU
and Davies, Melvyn B.
LU
- organization
- publishing date
- 2019-09-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- celestial mechanics, planet-star interactions, planetary systems, open clusters and associations: general, Astrophysics - Earth and Planetary Astrophysics
- in
- Monthly Notices of the Royal Astronomical Society
- volume
- 488
- issue
- 1
- pages
- 11 pages
- publisher
- Oxford University Press
- external identifiers
-
- scopus:85075156247
- ISSN
- 1365-2966
- DOI
- 10.1093/mnras/stz1794
- project
- IMPACT: Comets, asteroids and the habitability of planets
- Wallenberg Academy Fellow Project
- language
- English
- LU publication?
- yes
- id
- 94170fbc-12b3-4c6e-9d9b-c82504fe343e
- alternative location
- https://arxiv.org/abs/1902.09804
- date added to LUP
- 2019-07-26 13:50:49
- date last changed
- 2022-12-15 22:06:17
@article{94170fbc-12b3-4c6e-9d9b-c82504fe343e,
abstract = {{Stars formed in clusters can encounter other stars at close distances. In typical open clusters in the Solar neighbourhood containing hundreds or thousands of member stars, 10-20 per cent of Solar-mass member stars are expected to encounter another star at distances closer than 100 au. These close encounters strongly perturb the planetary systems, directly causing ejection of planets or their capture by the intruding star, as well as exciting the orbits. Using extensive N-body simulations, we study such fly-by encounters between two Solar system analogues, each with four giant planets from Jupiter to Neptune. We quantify the rates of loss and capture immediately after the encounter, e.g. the Neptune analogue is lost in one in four encounters within 100 au, and captured by the flying-by star in 1 in 12 encounters. We then perform long-term (up to 1 Gyr) simulations investigating the ensuing post-encounter evolution. We show that large numbers of planets are removed from systems due to planet-planet interactions and that captured planets further enhance the system instability. While encounters can initially leave a planetary system containing more planets by inserting additional ones, the long-term instability causes a net reduction in planet number. A captured planet ends up on a retrograde orbit in half of the runs in which it survives for 1Gyr; also, a planet bound to its original host star but flipped during the encounter may survive. Thus, encounters between planetary systems are a channel to create counter-rotating planets, This would happen in around 1 per cent of systems, and such planets are potentially detectable through astrometry or direct imaging.}},
author = {{Li, Daohai and Mustill, Alexander J. and Davies, Melvyn B.}},
issn = {{1365-2966}},
keywords = {{celestial mechanics; planet-star interactions; planetary systems; open clusters and associations: general; Astrophysics - Earth and Planetary Astrophysics}},
language = {{eng}},
month = {{09}},
number = {{1}},
pages = {{1366--1376}},
publisher = {{Oxford University Press}},
series = {{Monthly Notices of the Royal Astronomical Society}},
title = {{Fly-by encounters between two planetary systems I: Solar system analogues}},
url = {{http://dx.doi.org/10.1093/mnras/stz1794}},
doi = {{10.1093/mnras/stz1794}},
volume = {{488}},
year = {{2019}},
}