scholarly journals Simulation of 3 Body Exo-Planetary System Orbits

2020 ◽  
Vol 12 (2) ◽  
pp. 25
Author(s):  
Zixin Li

To find out the general motion model of exo-planetary systems with one star and two planets, a computer program was used to carry out simulations and generate graphs showing the orbits of planets. When given the orbital periods and masses of the planets and stars, it is possible to predict the location of the planets over time and plot the shape of the orbit by considering the gravitational interactions between planets and the star, assuming that the planetary orbits are co-planar. I used the program to reproduce the result of transit timing variations (TTVs) of Kepler-46 system, I then investigated on the magnitude of transit timing variations on a 3-body system with various masses and periods. I also ran simulations to investigate the pattern of orbits for different periods of planets in order to get a systematic conclusion.

2011 ◽  
Vol 28 (3) ◽  
pp. 177-201 ◽  
Author(s):  
Jean-Paul A. Zoghbi

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.


1977 ◽  
Vol 33 ◽  
pp. 175-187
Author(s):  
Su-Shu Huang

AbstractIn this paper we have discussed the origin of planetary systems on one hand and binary and multiple stars on the other. First we show that phenomenological differences between these two kinds of celestial objects are due to their genetic difference. The basic point is that formation of a planetary system around a star has to be a minor event in the life history of the star while formation of a binary or multiple system has to be an event that is important equally to all components of the system. Thus the planetary system evolves from a rotating disk of gaseous and dust particles that comes into being after the star has already been there. It is therefore reasonable to suggest that the rotating disk results from transfer of angular momentum from the central star to the surrounding medium which is likely a residue left over in the process of formation of the central star.Binary and multiple systems cannot be formed in this way because they do not show the characteristics of having come out of a rotating disk. The dominant mechanism of their formation is that they were formed naturally as they are, each from perhaps a single condensation in the interstellar medium. However such a single mechanism of formation cannot satisfactorily explain the observed spread of binaries in mean separations between two components (or equivalently orbital periods). But the disagreement may be removed by including a small number of binaries formed by other processes and by considering the change of orbital elements of binaries after their formation. Trapezia were likely formed also by more than one mechanism.That several stars could be formed, from a single condensation requires the” existence oí pre-stellar nuclei which are briefly: discussed at the end of the paper.


2020 ◽  
Vol 641 ◽  
pp. A38
Author(s):  
F. Gallet

Context. The presence of a massive close-in planet with an orbital period of a few days or less around a low-mass star can possibly result in a strong variation in the properties of the central star. Indeed, star-planet tidal interactions generate exchanges of angular momentum that can result in tidal spin-up. This effect could then lead to gyrochronological ages biased towards younger ages. Aims. This article provides the community with TATOO, a standalone tool based on tidal-chronology, with which to estimate the age of a massive close-in planetary system using only its observed properties: mass of the planet and the star, stellar rotation, and planetary orbital periods. Methods. I used a star-planet tidal evolution numerical code to create a large multi-parametric grid of the evolution of synthetic star-planet systems. Furthermore, using the tidal-chronology technique, I employed a 3D interpolation method to provide a fairly precise age estimate of any given planetary system composed of one massive close-in planet. Results. About half of the planetary systems investigated in this work are subject to tidal spin-up bias. I pointed out that this bias linearly scales with the ratio between rotation and orbital period, making this quantity a useful proxy to rapidly investigate whether tidal-chronology needs to be used. Moreover, while being model dependent, TATOO can also be used even if no rotational departure is present. In that case, it gives results in agreement with the classical gyrochronological analysis. Conclusions. TATOO is a useful tool specifically designed for massive close-in planetary systems that can also be used as a classical gyrochronological tool. For now it is the only publicly available software to estimate the age of massive close-in planetary systems subject to tidal spin-up. In that sense, tidal-chronology can be seen as a first order correction of the impact of tidal interaction on gyrochronology.


2012 ◽  
Vol 8 (S293) ◽  
pp. 171-173
Author(s):  
Wei Hao ◽  
M. B. N. Kouwenhoven

AbstractDistant stellar encouters can substantially affect the dynamical evolution of existing stellar and planetary systems (e.g., Malmberg et al. 2007; Spurzem et al. 2009). Although planets with small orbital periods are not directly affected by encountering stars, the secular evolution of a perturbed system may result in the ejection of the innermost planets, or physical collisions between the innermost planets and the host star, hundreds of thousands of years after a weak encounter with a neighboring star occurs. Here we present the results of our study on the cumulative effect of distant stellar encounters on multi-planet systems in star clusters, and how these results depend on the properties of the star cluster in which a planetary system is born (for details we refer to Hao & Kouwenhoven, in prep.). With our simulations we explain the scarcity of exoplanets in star clusters, not only for those in wide orbits (affected by stellar encounters), but also in close orbits (affected by the secular evolution of the system following an encounter).


Author(s):  
Asmita Bhandare ◽  
Susanne Pfalzner

Abstract Most stars form as part of a stellar group. These young stars are mostly surrounded by a disk from which potentially a planetary system might form. Both, the disk and later on the planetary system, may be affected by the cluster environment due to close fly-bys. The here presented database can be used to determine the gravitational effect of such fly-bys on non-viscous disks and planetary systems. The database contains data for fly-by scenarios spanning mass ratios between the perturber and host star from 0.3 to 50.0, periastron distances from 30 au to 1000 au, orbital inclination from 0∘ to 180∘ and angle of periastron of 0∘, 45∘ and 90∘. Thus covering a wide parameter space relevant for fly-bys in stellar clusters. The data can either be downloaded to perform one’s own diagnostics like for e.g. determining disk size, disk mass, etc. after specific encounters, obtain parameter dependencies or the different particle properties can be visualized interactively. Currently the database is restricted to fly-bys on parabolic orbits, but it will be extended to hyperbolic orbits in the future. All of the data from this extensive parameter study is now publicly available as DESTINY.


2020 ◽  
Vol 500 (2) ◽  
pp. 2711-2731
Author(s):  
Andrew Bunting ◽  
Caroline Terquem

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.


2018 ◽  
Vol 618 ◽  
pp. A116 ◽  
Author(s):  
J. Prieto-Arranz ◽  
E. Palle ◽  
D. Gandolfi ◽  
O. Barragán ◽  
E. W. Guenther ◽  
...  

Context. Multiplanet systems are excellent laboratories to test planet formation models as all planets are formed under the same initial conditions. In this context, systems transiting bright stars can play a key role, since planetary masses, radii, and bulk densities can be measured. Aims. GJ 9827 (K2-135) has recently been found to host a tightly packed system consisting of three transiting small planets whose orbital periods of 1.2, 3.6, and 6.2 days are near the 1:3:5 ratio. GJ 9827 hosts the nearest planetary system (~30 pc) detected by NASA’s Kepler or K2 space mission. Its brightness (V = 10.35 mag) makes the star an ideal target for detailed studies of the properties of its planets. Methods. Combining the K2 photometry with high-precision radial-velocity measurements gathered with the FIES, HARPS, and HARPS-N spectrographs we revised the system parameters and derive the masses of the three planets. Results. We find that GJ 9827 b has a mass of Mb = 3.69−0.46+0.48 M⊕ and a radius of Rb = 1.58−0.13+0.14 R⊕, yielding a mean density of ρb = 5.11−1.27+1.74 g cm−3. GJ 9827 c has a mass of Mc = 1.45−0.57+0.58 M⊕, radius of Rc = 1.24−0.11+0.11 R⊕, and a mean density of ρc = 4.13−1.77+2.31 g cm−3. For GJ 9827 d, we derive Md = 1.45−0.57+0.58 M⊕, Rd = 1.24−0.11+0.11 R⊕, and ρd = 1.51−0.53+0.71 g cm−3. Conclusions. GJ 9827 is one of the few known transiting planetary systems for which the masses of all planets have been determined with a precision better than 30%. This system is particularly interesting because all three planets are close to the limit between super-Earths and sub-Neptunes. The planetary bulk compositions are compatible with a scenario where all three planets formed with similar core and atmosphere compositions, and we speculate that while GJ 9827 b and GJ 9827 c lost their atmospheric envelopes, GJ 9827 d maintained its primordial atmosphere, owing to the much lower stellarirradiation. This makes GJ 9827 one of the very few systems where the dynamical evolution and the atmosphericescape can be studied in detail for all planets, helping us to understand how compact systems form and evolve.


Author(s):  
John Chambers ◽  
Jacqueline Mitton

This concluding chapter talks about how astronomers and space agencies in dozens of countries are helping to see the solar system as never before, transforming points of light into real worlds, and even bringing samples of those worlds back to Earth. At the same time, the stunning discovery of hundreds of other planetary systems in the galaxy has provided a powerful stimulus to understand how planetary systems form and evolve, and to find out what makes one system different from another. Moreover, in 2010, NASA announced its latest science plan. One of the key goals for NASA's future planetary science program is to learn how the Sun's family began and how it has changed over time. The chapter argues that the rapid pace of recent developments makes now a good time to take stock of what scholars know, even though the story is still incomplete.


2019 ◽  
Vol 492 (1) ◽  
pp. 352-368 ◽  
Author(s):  
Giorgi Kokaia ◽  
Melvyn B Davies ◽  
Alexander J Mustill

ABSTRACT We investigate the possibility of finding Earth-like planets in the habitable zone of 34 nearby FGK-dwarfs, each known to host one giant planet exterior to their habitable zone detected by RV. First we simulate the dynamics of the planetary systems in their present day configurations and determine the fraction of stable planetary orbits within their habitable zones. Then, we postulate that the eccentricity of the giant planet is a result of an instability in their past during which one or more other planets were ejected from the system. We simulate these scenarios and investigate whether planets orbiting in the habitable zone survive the instability. Explicitly we determine the fraction of test particles, originally found in the habitable zone, which remain in the habitable zone today. We label this fraction the resilient habitability of a system. We find that for most systems the probability of planets existing [or surviving] on stable orbits in the habitable zone becomes significantly smaller when we include a phase of instability in their history. We present a list of candidate systems with high resilient habitability for future observations. These are: HD 95872, HD 154345, HD 102843, HD 25015, GJ 328, HD 6718, and HD 150706. The known planets in the last two systems have large observational uncertainties on their eccentricities, which propagate into large uncertainties on their resilient habitability. Further observational constraints of these two eccentricities will allow us to better constrain the survivability of Earth-like planets in these systems.


2020 ◽  
Vol 635 ◽  
pp. A37 ◽  
Author(s):  
A. C. M. Correia ◽  
V. Bourrier ◽  
J.-B. Delisle

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.


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