The PAIRS project: a global formation model for planets in binaries. II. Gravitational perturbation effects from secondary stars

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Nigioni, Arianna, Venturini, Julia, Bolmont, Emeline, Turrini, Diego, Alibert, Yann, Emsenhuber, Alexandre
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908925859725312
author Nigioni, Arianna
Venturini, Julia
Bolmont, Emeline
Turrini, Diego
Alibert, Yann
Emsenhuber, Alexandre
author_facet Nigioni, Arianna
Venturini, Julia
Bolmont, Emeline
Turrini, Diego
Alibert, Yann
Emsenhuber, Alexandre
contents Roughly half of Sun-like stars have at least one stellar companion, whereas it is widely assumed that most known exoplanets orbit single stars, largely due to observational biases. However, astrometric surveys, direct imaging, and speckle interferometry are steadily increasing the number of confirmed exoplanets in binaries. A stellar companion introduces additional effects, such as circumstellar disk truncation and gravitational perturbations, which can strongly impact planet formation. While global planet formation models, for example the Bern model, have been broadly applied to single stars, modeling S-type binaries requires key modifications to capture these effects. This study extends the Bern model by incorporating the gravitational influence of a stellar companion into its N-body integrator, allowing us to quantify how this perturbation affects planetary formation and final system architecture across a range of binary configurations. By comparing binary and single-star systems under identical initial conditions, we can assess the specific impact of binary-induced dynamics. We ran three sets of simulations: (i) a grid of in situ single-embryo cases to quantify gravitational effects; (ii) formation simulations with and without migration to compare outcomes with single-star analogs; and (iii) multi-embryo runs to evaluate impacts on multi-planetary systems. Planets forming beyond half the host star's Hill radius are much more likely to become unbound especially in systems with high binary eccentricity. Even within stable zones, growth is suppressed by both reduced material availability and increased eccentricity from stellar perturbations. Both disk truncation and stellar perturbations must be included to model planet formation in S-type binaries accurately. Neglecting either one will end up misrepresenting planetary growth and survival.
format Preprint
id arxiv_https___arxiv_org_abs_2601_14215
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle The PAIRS project: a global formation model for planets in binaries. II. Gravitational perturbation effects from secondary stars
Nigioni, Arianna
Venturini, Julia
Bolmont, Emeline
Turrini, Diego
Alibert, Yann
Emsenhuber, Alexandre
Earth and Planetary Astrophysics
Roughly half of Sun-like stars have at least one stellar companion, whereas it is widely assumed that most known exoplanets orbit single stars, largely due to observational biases. However, astrometric surveys, direct imaging, and speckle interferometry are steadily increasing the number of confirmed exoplanets in binaries. A stellar companion introduces additional effects, such as circumstellar disk truncation and gravitational perturbations, which can strongly impact planet formation. While global planet formation models, for example the Bern model, have been broadly applied to single stars, modeling S-type binaries requires key modifications to capture these effects. This study extends the Bern model by incorporating the gravitational influence of a stellar companion into its N-body integrator, allowing us to quantify how this perturbation affects planetary formation and final system architecture across a range of binary configurations. By comparing binary and single-star systems under identical initial conditions, we can assess the specific impact of binary-induced dynamics. We ran three sets of simulations: (i) a grid of in situ single-embryo cases to quantify gravitational effects; (ii) formation simulations with and without migration to compare outcomes with single-star analogs; and (iii) multi-embryo runs to evaluate impacts on multi-planetary systems. Planets forming beyond half the host star's Hill radius are much more likely to become unbound especially in systems with high binary eccentricity. Even within stable zones, growth is suppressed by both reduced material availability and increased eccentricity from stellar perturbations. Both disk truncation and stellar perturbations must be included to model planet formation in S-type binaries accurately. Neglecting either one will end up misrepresenting planetary growth and survival.
title The PAIRS project: a global formation model for planets in binaries. II. Gravitational perturbation effects from secondary stars
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2601.14215