Asynchronous and chaotic rotation for compact planetary systems

2020 ◽  
Author(s):  
Alexandre C. M. Correia ◽  
Jean-Baptiste Delisle
Keyword(s):  
Orbital Period ◽  
Spin Dynamics ◽  
Rotation Period ◽  
Planetary Systems ◽  
Circular Orbits ◽  
Simple Method ◽  
Tidal Dissipation ◽  
Orbital Perturbations ◽  
Spin Evolution

<p>We study the spin evolution of close-in planets in compact multi-planetary systems. The rotation period of these planets is often assumed to be synchronous with the orbital period due to tidal dissipation. Here we show that planet-planet perturbations can drive the spin of these planets into non-synchronous or even chaotic states. These asynchronous configurations are possible even for nearly circular orbits and will impact the habitability of these planets. We also present a very simple method to probe the spin dynamics from the orbital perturbations.</p>

scholarly journals Spin dynamics of close-in planets exhibiting large transit timing variations

2017 ◽  
Vol 605 ◽  
pp. A37 ◽  
Author(s):  
J.-B. Delisle ◽  
A. C. M. Correia ◽  
A. Leleu ◽  
P. Robutel
Keyword(s):  
Numerical Simulations ◽  
Orbital Period ◽  
Spin Dynamics ◽  
Rotation Period ◽  
Tidal Dissipation ◽  
Link Type ◽  
Spin Evolution ◽  
Synchronous Rotation ◽  
The Mean ◽  
Good Probe

We study the spin evolution of close-in planets in compact multi-planetary systems. The rotation period of these planets is often assumed to be synchronous with the orbital period due to tidal dissipation. Here we show that planet-planet perturbations can drive the spin of these planets into non-synchronous or even chaotic states. In particular, we show that the transit timing variation (TTV) is a very good probe to study the spin dynamics, since both are dominated by the perturbations of the mean longitude of the planet. We apply our model to KOI-227 b and Kepler-88 b, which are both observed undergoing strong TTVs. We also perform numerical simulations of the spin evolution of these two planets. We show that for KOI-227 b non-synchronous rotation is possible, while for Kepler-88 b the rotation can be chaotic.

scholarly journals Quantization of Planetary Systems and its Dependency on Stellar Rotation

2011 ◽  
Vol 28 (3) ◽  
pp. 177-201 ◽  
Author(s):  
Jean-Paul A. Zoghbi
Keyword(s):  
Gravitational Instability ◽  
Rotation Period ◽  
Planetary Systems ◽  
Stellar Rotation ◽  
Tidal Dissipation ◽  
Half Integer ◽  
Pure Chance ◽  
Rotation Periods ◽  
Planetary Orbits ◽  
Orbital Periods

AbstractWith the discovery of now more than 500 exoplanets, we present a statistical analysis of the planetary orbital periods and their relationship to the rotation periods of their parent stars. We test whether the structural variables of planetary orbits, i.e. planetary angular momentum and orbital period, are ‘quantized’ in integer or half-integer multiples of the parent star's rotation period. The Solar System is first shown to exhibit quantized planetary orbits that correlate with the Sun's rotation period. The analysis is then expanded over 443 exoplanets to statistically validate this quantization and its association with stellar rotation. The results imply that the exoplanetary orbital periods are highly correlated with the parent star's rotation periods and follow a discrete half-integer relationship with orbital ranks n = 0.5, 1.0, 1.5, 2.0, 2.5, etc. The probability of obtaining these results by pure chance is p < 0.024. We discuss various mechanisms that could justify this planetary quantization, such as the hybrid gravitational instability models of planet formation, along with possible physical mechanisms such as the inner disc's magnetospheric truncation, tidal dissipation, and resonance trapping. In conclusion, we statistically demonstrate that a quantized orbital structure should emerge from the formation processes of planetary systems and that this orbital quantization is highly dependent on the parent star's rotation period.

scholarly journals Spin-orbit resonances and rotation of coorbital bodies in quasi-circular orbits

2014 ◽  
Vol 9 (S310) ◽  
pp. 9-12
Author(s):  
Robutel Philippe ◽  
C. M. Correia Alexandre ◽  
Leleu Adrien
Keyword(s):  
Orbital Period ◽  
Central Body ◽  
Rotation Period ◽  
Spin Orbit ◽  
Circular Orbits ◽  
Keplerian Orbits ◽  
Wide Range ◽  
Synchronous Rotation ◽  
Order Of Magnitude ◽  
Body Shapes

AbstractThe rotation of asymmetric bodies in eccentric Keplerian orbits can be chaotic when there is some overlap of spin-orbit resonances. Here we show that the rotation of two coorbital bodies (two planets orbiting a star or two satellites of a planet) can also be chaotic even for quasi-circular orbits around the central body. When dissipation is present, the rotation period of a body on a nearly circular orbit is believed to always end synchronous with the orbital period. Here we demonstrate that for coorbital bodies in quasi-circular orbits, stable non-synchronous rotation is possible for a wide range of mass ratios and body shapes. We further show that the rotation becomes chaotic when the natural rotational libration frequency, due to the axial asymmetry, is of the same order of magnitude as the orbital libration frequency.

scholarly journals Spin-orbit coupling for close-in planets

2019 ◽  
Vol 630 ◽  
pp. A102 ◽  
Author(s):  
Alexandre C. M. Correia ◽  
Jean-Baptiste Delisle
Keyword(s):  
Spin Dynamics ◽  
Orbit Coupling ◽  
New Method ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Circular Orbits ◽  
Tidal Torque ◽  
Orbital Perturbations ◽  
Multi Body ◽  
Orbit Problem

We study the spin evolution of close-in planets in multi-body systems and present a very general formulation of the spin-orbit problem. This includes a simple way to probe the spin dynamics from the orbital perturbations, a new method for computing forced librations and tidal deformation, and general expressions for the tidal torque and capture probabilities in resonance. We show that planet–planet perturbations can drive the spin of Earth-size planets into asynchronous or chaotic states, even for nearly circular orbits. We apply our results to Mercury and to the KOI-1599 system of two super-Earths in a 3/2 mean motion resonance.

scholarly journals Tidally induced stellar oscillations: converting modelled oscillations excited by hot Jupiters into observables

2020 ◽  
Vol 500 (2) ◽  
pp. 2711-2731
Author(s):  
Andrew Bunting ◽  
Caroline Terquem
Keyword(s):  
Radial Velocity ◽  
Orbital Period ◽  
Planetary Systems ◽  
Velocity Signal ◽  
Convective Flux ◽  
Hot Jupiters ◽  
Stellar Oscillations ◽  
Orbital Periods ◽  
Hot Jupiter

ABSTRACT We calculate the conversion from non-adiabatic, non-radial oscillations tidally induced by a hot Jupiter on a star to observable spectroscopic and photometric signals. Models with both frozen convection and an approximation for a perturbation to the convective flux are discussed. Observables are calculated for some real planetary systems to give specific predictions. The photometric signal is predicted to be proportional to the inverse square of the orbital period, P−2, as in the equilibrium tide approximation. However, the radial velocity signal is predicted to be proportional to P−1, and is therefore much larger at long orbital periods than the signal corresponding to the equilibrium tide approximation, which is proportional to P−3. The prospects for detecting these oscillations and the implications for the detection and characterization of planets are discussed.

Longevity of moons around habitable planets

2014 ◽  
Vol 13 (4) ◽  
pp. 324-336 ◽  
Author(s):  
Takashi Sasaki ◽  
Jason W. Barnes
Keyword(s):  
Orbital Period ◽  
Extrasolar Planets ◽  
The Sun ◽  
Habitable Zone ◽  
Evolution Theory ◽  
Earth System ◽  
The Moon ◽  
Tidal Dissipation ◽  
Habitable Planets ◽  
Rocky Planets

AbstractWe consider tidal decay lifetimes for moons orbiting habitable extrasolar planets using the constant Q approach for tidal evolution theory. Large moons stabilize planetary obliquity in some cases, and it has been suggested that large moons are necessary for the evolution of complex life. We find that the Moon in the Sun–Earth system must have had an initial orbital period of not slower than 20 h rev−1 for the moon's lifetime to exceed a 5 Gyr lifetime. We assume that 5 Gyr is long enough for life on planets to evolve complex life. We show that moons of habitable planets cannot survive for more than 5 Gyr if the stellar mass is less than 0.55 and 0.42 M⊙ for Qp=10 and 100, respectively, where Qp is the planetary tidal dissipation quality factor. Kepler-62e and f are of particular interest because they are two actually known rocky planets in the habitable zone. Kepler-62e would need to be made of iron and have Qp=100 for its hypothetical moon to live for longer than 5 Gyr. A hypothetical moon of Kepler-62f, by contrast, may have a lifetime greater than 5 Gyr under several scenarios, and particularly for Qp=100.

scholarly journals X-ray binaries with neutron stars at different accretion stages

2018 ◽  
Vol 14 (S346) ◽  
pp. 219-227
Author(s):  
Konstantin A. Postnov ◽  
Alexander G. Kuranov ◽  
Lev R. Yungelson
Keyword(s):  
Magnetic Fields ◽  
Neutron Stars ◽  
Orbital Period ◽  
Population Synthesis ◽  
Circular Orbits ◽  
X Ray ◽  
Accretion Rates ◽  
Supercritical Accretion ◽  
Binary Evolution ◽  
X Ray Binaries

Abstract. Different accretion regimes onto magnetized NSs in HMXBs are considered: wind-fed supersonic (Bondi) regime at high accretion rates <math/> g s-1, subsonic settling regime at lower <math/> and supercritical disc accretion during Roche lobe overflow. In wind-fed stage, NSs in HMXBs reach equilibrium spin periods P* proportional to binary orbital period Pb. At supercritical accretion stage, the system may appear as a pulsating ULX. Population synthesis of Galactic HMXBs using standard assumptions on the binary evolution and NS formation is presented. Comparison of the model P* – Pb (the Corbet diagram), P* – Lx and Pb – Lx distributions with those for the observed HMXBs (including Be X-ray binaries) and pulsating ULXs suggests the importance of the reduction of P* in non-circular orbits, explaining the location of Be X-ray binaries in the model Corbet diagram, and the universal parameters of pulsating ULXs depending only on the NS magnetic fields.

scholarly journals Why do warm Neptunes present nonzero eccentricity?

2020 ◽  
Vol 635 ◽  
pp. A37 ◽  
Author(s):  
A. C. M. Correia ◽  
V. Bourrier ◽  
J.-B. Delisle
Keyword(s):  
Planetary Systems ◽  
Atmospheric Tides ◽  
Tidal Dissipation ◽  
Bodily Tides ◽  
Orbital Periods

Most Neptune-mass planets in close-in orbits (orbital periods less than a few days) present nonzero eccentricity, typically around 0.15. This is somehow unexpected, as these planets undergo strong tidal dissipation that should circularize their orbits in a timescale shorter than the age of the system. In this paper we discuss some mechanisms that can oppose to bodily tides, namely, thermal atmospheric tides, evaporation of the atmosphere, and excitation from a distant companion. In the first two cases, the eccentricity can increase consistently, while in the last one, the eccentricity can only be excited for a limited amount of time (that may nevertheless exceed the age of the system). We show the limitations of these different mechanisms and how some of them could, depending on specific properties of the observed planetary systems, account for their presently observed eccentricities.

scholarly journals Orbital Evolution of Planetary Systems

2004 ◽  
Vol 202 ◽  
pp. 175-177
Author(s):  
Tapan K. Chatterjee ◽  
V. B. Magalinsky
Keyword(s):  
Solar System ◽  
Ground State ◽  
Minimum Energy ◽  
Orbital Stability ◽  
Planetary Systems ◽  
Active Role ◽  
Orbital Evolution ◽  
Circular Orbits ◽  
Tidal Forces

It is significant that the orbits of the planets in the solar system are very nearly circular, except for Mercury and Pluto where, conceivably, due to their comparatively small sizes, the tidal forces have played a less active role. Most of the suspected planets orbiting pulsars have nearly circular orbits. These systems tend to have minimum energy and are subjected to tidal forces. We find that a planet circularizes its orbit, in an effort to attain orbital stability and the ground state. Details can be found in Magalinsky & Chatterjee, 1997, and Magalinsky and Chatterjee, 2000.

scholarly journals Optical and UV Observations of the Intermediate Polar 3A0729+103. Modulation with the Orbital Period

1987 ◽  
Vol 93 ◽  
pp. 631-635
Author(s):  
R. Falomo ◽  
J.M. Bonnet-Bidaud ◽  
P.A. Charles ◽  
L. Maraschi ◽  
M. Mouchet ◽  
...  
Keyword(s):  
Orbital Period ◽  
Rotation Period ◽  
Spectral Features ◽  
X Ray

Abstract3A0729+103 (= BG CMi) is an intermediate polar discovered through its X-ray emission (McHardy et al. 1981, 1984). The orbital period is 3.235 hours and the rotation period is 15.2 minutes, For ephemeris and references on the source we refer to McHardy et al. (1984). We report here on optical (4025 to 5090 A) and ultraviolet (1200 to 3200 A) spectroscopy obtained, respectively, on Dec 1, 1984 and April 21, 1985. Our data show clear modulation of spectral features with the orbital period.

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