On the origin of the solar system

3. The essential requirement that the nova must satisfy in the above theory is that the total mass in the form of diffuse gaseous material must be of the order of 1/10 the solar mass, which requirement seems to be consistent with the observations of novae. Thus, although the theory applies explicitly to novae that break into two pieces of stellar mass having a gaseous filament drawn out between them (the pieces may have a mass ratio as great as 5/1), it seems clear that the discussion could be adjusted to include the case of novae following other models.The process described above can be applied to the formation of non-solar planets. The mass of available planetary material depends upon such factors as the mass of the nova and its separation from the companion before outburst. It is to be expected that variations in these factors can lead to planetary masses that vary over a fairly wide range. It follows that since an appreciable fraction of the stars of mass comparable or greater than the solar mass are known to be members of binary systems, the number of planetary systems must be at least of the same order as the number of novae that have occurred in this class of star.

Download Full-text

Bayesian constraints on the origin and geology of exo-planetary material using a population of externally polluted white dwarfs

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab736 ◽

2021 ◽

Author(s):

John H D Harrison ◽

Amy Bonsor ◽

Mihkel Kama ◽

Andrew M Buchan ◽

Simon Blouin ◽

...

Keyword(s):

Solar System ◽

White Dwarf ◽

Bayesian Model ◽

Total Mass ◽

White Dwarfs ◽

Bulk Composition ◽

Planetary Systems ◽

The Moon ◽

Planetary Bodies ◽

Nearby Stars

Abstract White dwarfs that have accreted planetary bodies are a powerful probe of the bulk composition of exoplanetary material. In this paper, we present a Bayesian model to explain the abundances observed in the atmospheres of 202 DZ white dwarfs by considering the heating, geochemical differentiation, and collisional processes experienced by the planetary bodies accreted, as well as gravitational sinking. The majority (>60%) of systems are consistent with the accretion of primitive material. We attribute the small spread in refractory abundances observed to a similar spread in the initial planet-forming material, as seen in the compositions of nearby stars. A range in Na abundances in the pollutant material is attributed to a range in formation temperatures from below 1,000 K to higher than 1,400 K, suggesting that pollutant material arrives in white dwarf atmospheres from a variety of radial locations. We also find that Solar System-like differentiation is common place in exo-planetary systems. Extreme siderophile (Fe, Ni or Cr) abundances in 8 systems require the accretion of a core-rich fragment of a larger differentiated body to at least a 3σ significance, whilst one system shows evidence that it accreted a crust-rich fragment. In systems where the abundances suggest that accretion has finished (13/202), the total mass accreted can be calculated. The 13 systems are estimated to have accreted masses ranging from the mass of the Moon to half that of Vesta. Our analysis suggests that accretion continues for 11Myrs on average.

Download Full-text

Energy optimization in extrasolar planetary systems: the transition from peas-in-a-pod to runaway growth

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa624 ◽

2020 ◽

Vol 493 (4) ◽

pp. 5520-5531 ◽

Cited By ~ 1

Author(s):

Fred C Adams ◽

Konstantin Batygin ◽

Anthony M Bloch ◽

Gregory Laughlin

Keyword(s):

Binary Stars ◽

Total Mass ◽

Extrasolar Planets ◽

Energy State ◽

Critical Mass ◽

Energy Optimization ◽

Planetary Systems ◽

Equal Mass ◽

Wide Range ◽

Self Gravity

ABSTRACT Motivated by the trends found in the observed sample of extrasolar planets, this paper determines tidal equilibrium states for forming planetary systems – subject to conservation of angular momentum, constant total mass, and fixed orbital spacing. In the low mass limit, valid for super-Earth-class planets with masses of order mp ∼ 10 M⊕, previous work showed that energy optimization leads to nearly equal mass planets, with circular orbits confined to a plane. The present treatment generalizes previous results by including the self-gravity of the planetary bodies. For systems with a sufficiently large total mass $m_{\scriptstyle \rm T}$ in planets, the optimized energy state switches over from the case of nearly equal mass planets to a configuration where one planet contains most of the material. This transition occurs for a critical mass threshold of approximately $m_{\scriptstyle \rm T}\gtrsim m_{\scriptstyle \rm C}\sim 40\,{\rm M_\oplus}$ (where the value depends on the semimajor axes of the planetary orbits, the stellar mass, and other system properties). These considerations of energy optimization apply over a wide range of mass scales, from binary stars to planetary systems to the collection of moons orbiting the giant planets in our Solar system.

Download Full-text

Trojans in Exosystems with Two Massive Planets

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313012726 ◽

2012 ◽

Vol 8 (S293) ◽

pp. 152-158 ◽

Cited By ~ 1

Author(s):

Rudolf Dvorak ◽

Li-Yong Zhou ◽

Helmut Baudisch

Keyword(s):

Numerical Integration ◽

Equilibrium Points ◽

Planetary Systems ◽

Central Star ◽

Giant Planets ◽

Dynamical Model ◽

Outer Planet ◽

Mass Ratio ◽

Wide Range ◽

Mass Ratios

AbstractWe take as dynamical model for extrasolar planetary systems a central star like our Sun and two giant planets m1 and m2 like Jupiter and Saturn. We change the mass ratio μ=m2/m1 of the two large planets for a wide range of 1/16 < μ < 16. We also change the ratio between the initial semi-major axes (ν=a2/a1) in the range of 1.2 < ν < 3 to model the different architecture of extrasolar planetary systems hosting two giant planets. The results for possible Trojans (Trojan planets) in the equilateral equilibrium points of the inner planet m1 and the outer planet m2 were derived with the aid of numerical integration. It turned out that in many configurations – depending on the mass ratios μ and the semi-major axes ratio ν – giant planets may host Trojans.

Download Full-text

Characterizing planetesimal belts through the study of debris dust

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311019934 ◽

2010 ◽

Vol 6 (S276) ◽

pp. 54-59

Author(s):

Amaya Moro-Martín

Keyword(s):

Solar System ◽

Main Sequence ◽

Planetary Systems ◽

Dust Particles ◽

Debris Disks ◽

Main Sequence Stars ◽

Wide Range ◽

Robust Process

AbstractMain sequence stars are commonly surrounded by disks of dust. From lifetime arguments, it is inferred that the dust particles are not primordial but originate from the collision of planetesimals, similar to the asteroids, comets and KBOs in our Solar system. The presence of these debris disks around stars with a wide range of masses, luminosities, and metallicities, with and without binary companions, is evidence that planetesimal formation is a robust process that can take place under a wide range of conditions. Debris disks can help us learn about the formation, evolution and diversity of planetary systems.

Download Full-text

Fly-by encounters between two planetary systems I: Solar system analogues

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz1794 ◽

2019 ◽

Vol 488 (1) ◽

pp. 1366-1376 ◽

Cited By ~ 11

Author(s):

Daohai Li ◽

Alexander J Mustill ◽

Melvyn B Davies

Keyword(s):

Solar System ◽

Planetary System ◽

Planetary Systems ◽

Open Clusters ◽

Giant Planets ◽

Direct Imaging ◽

Solar Mass ◽

Close Encounters ◽

Large Numbers

ABSTRACTStars 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.

Download Full-text

Breaking down the link between luminous and dark matter in massive galaxies

Proceedings of the International Astronomical Union ◽

10.1017/s174392131102299x ◽

2010 ◽

Vol 6 (S277) ◽

pp. 305-308

Author(s):

Sébastien Foucaud ◽

Christopher J. Conselice

Keyword(s):

Dark Matter ◽

Total Mass ◽

Mass Range ◽

Stellar Mass ◽

Wide Field ◽

Mass Ratio ◽

Massive Galaxies ◽

Halo Masses ◽

Stellar Masses ◽

Baryonic Mass

AbstractWe present a study on the clustering of a stellar mass selected sample of galaxies with stellar masses M* > 1010M⊙ at redshifts 0.4 < z < 2.0, taken from the Palomar Observatory Wide-field Infrared Survey. We examine the clustering properties of these stellar mass selected samples as a function of redshift and stellar mass, and find that galaxies with high stellar masses have a progressively higher clustering strength than galaxies with lower stellar masses. We also find that galaxies within a fixed stellar mass range have a higher clustering strength at higher redshifts. We further estimate the average total masses of the dark matter haloes hosting these stellar-mass selected galaxies. For all galaxies in our sample the stellar-mass-to-total-mass ratio is always lower than the universal baryonic mass fraction and the stellar-mass-to-total-mass ratio is strongly correlated with the halo masses for central galaxies, such that more massive haloes contain a lower fraction of their mass in the form of stars. The remaining baryonic mass is included partially in stars within satellite galaxies in these haloes, and as diffuse hot and warm gas. We also find that, at a fixed stellar mass, the stellar-to-total-mass ratio increases at lower redshifts. This suggests that galaxies at a fixed stellar mass form later in lower mass dark matter haloes, and earlier in massive haloes. We interpret this as a ‘halo downsizing’ effect.

Download Full-text

Episodes of Emission Lines in the Spectra of Red Giants as Signatures of Remnant Planetary Systems

Symposium - International Astronomical Union ◽

10.1017/s0074180900217646 ◽

2004 ◽

Vol 202 ◽

pp. 115-117

Author(s):

G. M. Rudnitskij

Keyword(s):

Solar System ◽

Short Distance ◽

Planetary System ◽

Planetary Systems ◽

Emission Lines ◽

Circumstellar Envelope ◽

Red Giants ◽

Medium Effects ◽

Solar Mass ◽

Red Giant

When a star with a mass of about 1 solar mass enters the red giant stage of its evolution, the radius of its atmosphere reaches several astronomical units. If the star possessed during its mainsequence life a planetary system, similar to the solar system, the planets will be embedded into a rather dense and hot medium. Effects of a planet revolving around a red giant at a short distance (inside its circumstellar envelope) are discussed. Systematic monitoring of the spectra of red giants may reveal periodicities in the emergence of shock-induced emission lines and thus to detect probable remnant planetary systems around these stars.

Download Full-text

The structure of the co-orbital stable regions as a function of the mass ratio

10.5194/epsc2020-927 ◽

2020 ◽

Author(s):

Luana Liberato ◽

Othon Winter

Keyword(s):

Solar System ◽

Numerical Simulations ◽

Asteroid Belt ◽

Stable Region ◽

Mass Ratio ◽

Astronomical Society ◽

Royal Astronomical Society ◽

Astrophysical Journal ◽

Wide Range ◽

Orbital Region

In the past years, astronomers have discovered many non-planetary structures in extrasolar systems such as a comet (Kiefer et al. 2014), an asteroid belt (Moro-Mart&#237;n et al. 2008), an exoplanetary ring (Kenworthy & Mamajek 2015), and more recently the formation of an exomoon (Isella et al. 2019). But, although the search for exotrojans has not had success so far (e.g. Lillo-Box, J. et al. 2018), they must be as common as they are in the Solar System. Co-orbital systems were widely studied, and there are several works on stability and the formation of these structures. However, for the size and location of the stable regions, authors usually describe their results but do not provide a way to find them without numerical simulations and, in most works, the mass ratio value range is small. In the current work, we aimed to study the structure of co-orbital stable regions for a wide range of mass ratio systems and built empirical equations to describe them. It allows estimating the size and location of co-orbital stable regions from a few system&#8217;s parameters. In our recently published work (Liberato & Winter 2020), we have distributed thousands of massless particles in the co-orbital region of a massive secondary body adopting the planar circular restricted three-body problem. Using the N-body integrator Mercury (Chambers 1999) with the Bulirsh-Stoer integrator, we performed numerical simulations for a wide range of mass ratios (&#956;) for 7x105 orbital periods of the secondary body. We divided the results into two groups, the horseshoe and tadpole stable regions. We found that the horseshoe regions upper limit is between 9.539 &#215; 10-4< &#956; < 1.192 &#215; 10-3, which correspond to a minimum angular distance from the secondary to the separatrix between 27.239&#176; and 27.802&#176;. We also found that the limit to exist stability in the co-orbital region is about &#956; = 2.3313 &#215; 10-2. That value is much smaller than the predicted by the linear theory, but we haven&#8217;t studied the stability for mass ratio values greater than 2.785&#215;10-2. We have fitted polynomial functions to our results to describe the stable region parameters to represent estimates of the maximum angular and radial widths of the co-orbital stable regions for any system with 9.547 &#215; 10-5 &#8804; &#956; &#8804; 2.331 &#215; 10-2. &#160; References: -Chambers J. E., 1999, Monthly Notices of the Royal Astronomical Society, 304, 793 -Isella A., Benisty M., Teague R., Bae J., Keppler M., Facchini S., P&#233;rez L.,2019, The Astrophysical Journal, 879, L25 -Kenworthy M. A., Mamajek E. E., 2015, The Astrophysical Journal, 800, 126 -Kiefer F., Lecavelier des Etangs A., Boissier J., Vidal-Madjar A., Beust H., Lagrange A. M., H&#233;brard G., Ferlet R., 2014, Nature, 514, 462 -L. Liberato, O. C. Winter, The structure of the co-orbital stable regions as a function of the mass ratio, 2020, Monthly Notices of the Royal Astronomical Society, , staa1727,&#160;<a href="https://doi.org/10.1093/mnras/staa1727">https://doi.org/10.1093/mnras/staa1727</a> -Lillo-Box, J. Barrado, D. Figueira, P. Leleu, A. Santos, N. C. Correia, A. C. M. Robutel, P. Faria, J. P. 2018, Astronomy & Astrophysics, 609, A96 -Moro-Mart&#237;n A., Wyatt M. C., Malhotra R., Trilling D. E., 2008, The Solar System Beyond Neptune, p. 465

Download Full-text

Seismic probing of the first dredge-up event through the eccentric red-giant and red-giant spectroscopic binary KIC 9163796

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731269 ◽

2018 ◽

Vol 612 ◽

pp. A22 ◽

Cited By ~ 14

Author(s):

P. G. Beck ◽

T. Kallinger ◽

K. Pavlovski ◽

A. Palacios ◽

A. Tkachenko ◽

...

Keyword(s):

Stellar Evolution ◽

Binary Systems ◽

Rotation Period ◽

Stellar Mass ◽

Strong Impact ◽

Mass Ratio ◽

Lithium Abundance ◽

Convective Envelope ◽

Surface Rotation ◽

Red Giant

Context. Binaries in double-lined spectroscopic systems (SB2) provide a homogeneous set of stars. Differences of parameters, such as age or initial conditions, which otherwise would have strong impact on the stellar evolution, can be neglected. The observed differences are determined by the difference in stellar mass between the two components. The mass ratio can be determined with much higher accuracy than the actual stellar mass. Aim. In this work, we aim to study the eccentric binary system KIC 9163796, whose two components are very close in mass and both are low-luminosity red-giant stars. Methods. We analysed four years of Kepler space photometry and we obtained high-resolution spectroscopy with the Hermes instrument. The orbital elements and the spectra of both components were determined using spectral disentangling methods. The effective temperatures, and metallicities were extracted from disentangled spectra of the two stars. Mass and radius of the primary were determined through asteroseismology. The surface rotation period of the primary is determined from the Kepler light curve. From representative theoretical models of the star, we derived the internal rotational gradient, while for a grid of models, the measured lithium abundance is compared with theoretical predictions. Results. From seismology the primary of KIC 9163796 is a star of 1.39 ± 0.06M⊙, while the spectroscopic mass ratio between both components can be determined with much higher precision by spectral disentangling to be 1.015 ± 0.005. With such mass and a difference in effective temperature of 600 K from spectroscopy, the secondary and primary are, respectively, in the early and advanced stage of the first dredge-up event on the red-giant branch. The period of the primary’s surface rotation resembles the orbital period within ten days. The radial rotational gradient between the surface and core in KIC 9163796 is found to be 6.9−1.0+2.0. This is a low value but not exceptional if compared to the sample of typical single field stars. The seismic average of the envelope’s rotation agrees with the surface rotation rate. The lithium’abundance is in agreement with quasi rigidly rotating models. Conclusions. The agreement between the surface rotation with the seismic result indicates that the full convective envelope is rotating quasi-rigidly. The models of the lithium abundance are compatible with a rigid rotation in the radiative zone during the main sequence. Because of the many constraints offered by oscillating stars in binary systems, such objects are important test beds of stellar evolution.

Download Full-text