Can planetary instability explain the Kepler dichotomy?
Johansen, Anders LU ; Davies, Melvyn B LU ; Church, Ross LU
and Holmelin, Viktor
(2012)
In Astrophysical Journal
758(1).
- Abstract
- The planet candidates discovered by the Kepler mission provide a rich sample to constrain the architectures and relative inclinations of planetary systems within approximately 0.5 AU of their host stars. We use the triple-transit systems from the Kepler 16 months data as templates for physical triple-planet systems and perform synthetic transit observations, varying the internal inclination variation of the orbits. We find that all the Kepler triple-transit and double-transit systems can be produced from the triple-planet templates, given a low mutual inclination of around 5 degrees. Our analysis shows that the Kepler data contain a population of planets larger than four Earth radii in single-transit systems that cannot arise from the... (More)
- The planet candidates discovered by the Kepler mission provide a rich sample to constrain the architectures and relative inclinations of planetary systems within approximately 0.5 AU of their host stars. We use the triple-transit systems from the Kepler 16 months data as templates for physical triple-planet systems and perform synthetic transit observations, varying the internal inclination variation of the orbits. We find that all the Kepler triple-transit and double-transit systems can be produced from the triple-planet templates, given a low mutual inclination of around 5 degrees. Our analysis shows that the Kepler data contain a population of planets larger than four Earth radii in single-transit systems that cannot arise from the triple-planet templates. We explore the hypothesis that high-mass counterparts of the triple-transit systems underwent dynamical instability to produce a population of massive double-planet systems of moderately high mutual inclination. We perform N-body simulations of mass-boosted triple-planet systems and observe how the systems heat up and lose planets by planet-planet collisions, and less frequently by ejections or collisions with the star, yielding transits in agreement with the large planets in the Kepler single-transit systems. The resulting population of massive double-planet systems nevertheless cannot explain the additional excess of low-mass planets among the observed single-transit systems and the lack of gas-giant planets in double-transit and triple-transit systems. Planetary instability of systems of triple gas-giant planets can be behind part of the dichotomy between systems hosting one or more small planets and those hosting a single giant planet. The main part of the dichotomy, however, is more likely to have arisen already during planet formation when the formation, migration, or scattering of a massive planet, triggered above a threshold metallicity, suppressed the formation of other planets in sub-AU orbits. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/3181380
- author
- Johansen, Anders
LU
; Davies, Melvyn B
LU
; Church, Ross
LU
and Holmelin, Viktor
- organization
- publishing date
- 2012
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- planets and satellites: dynamical evolution and stability, planets and, satellites: formation, protoplanetary disks
- in
- Astrophysical Journal
- volume
- 758
- issue
- 1
- article number
- 39
- publisher
- American Astronomical Society
- external identifiers
-
- wos:000309520500039
- scopus:84866950534
- ISSN
- 0004-637X
- DOI
- 10.1088/0004-637X/758/1/39
- language
- English
- LU publication?
- yes
- id
- dc75902e-0e5a-4aa7-8b94-104bb9d6fea6 (old id 3181380)
- date added to LUP
- 2016-04-01 13:10:43
- date last changed
- 2024-02-07 21:45:10
@article{dc75902e-0e5a-4aa7-8b94-104bb9d6fea6,
abstract = {{The planet candidates discovered by the Kepler mission provide a rich sample to constrain the architectures and relative inclinations of planetary systems within approximately 0.5 AU of their host stars. We use the triple-transit systems from the Kepler 16 months data as templates for physical triple-planet systems and perform synthetic transit observations, varying the internal inclination variation of the orbits. We find that all the Kepler triple-transit and double-transit systems can be produced from the triple-planet templates, given a low mutual inclination of around 5 degrees. Our analysis shows that the Kepler data contain a population of planets larger than four Earth radii in single-transit systems that cannot arise from the triple-planet templates. We explore the hypothesis that high-mass counterparts of the triple-transit systems underwent dynamical instability to produce a population of massive double-planet systems of moderately high mutual inclination. We perform N-body simulations of mass-boosted triple-planet systems and observe how the systems heat up and lose planets by planet-planet collisions, and less frequently by ejections or collisions with the star, yielding transits in agreement with the large planets in the Kepler single-transit systems. The resulting population of massive double-planet systems nevertheless cannot explain the additional excess of low-mass planets among the observed single-transit systems and the lack of gas-giant planets in double-transit and triple-transit systems. Planetary instability of systems of triple gas-giant planets can be behind part of the dichotomy between systems hosting one or more small planets and those hosting a single giant planet. The main part of the dichotomy, however, is more likely to have arisen already during planet formation when the formation, migration, or scattering of a massive planet, triggered above a threshold metallicity, suppressed the formation of other planets in sub-AU orbits.}},
author = {{Johansen, Anders and Davies, Melvyn B and Church, Ross and Holmelin, Viktor}},
issn = {{0004-637X}},
keywords = {{planets and satellites: dynamical evolution and stability; planets and; satellites: formation; protoplanetary disks}},
language = {{eng}},
number = {{1}},
publisher = {{American Astronomical Society}},
series = {{Astrophysical Journal}},
title = {{Can planetary instability explain the Kepler dichotomy?}},
url = {{http://dx.doi.org/10.1088/0004-637X/758/1/39}},
doi = {{10.1088/0004-637X/758/1/39}},
volume = {{758}},
year = {{2012}},
}