The distribution of mass in the planetary system and solar nebula

1977 ◽  
Vol 51 (1) ◽  
pp. 153-158 ◽  
Author(s):  
S. J. Weidenschilling
Keyword(s):  
Solar Nebula ◽  
Planetary System

scholarly journals Heliocentric Zoning of the Asteroid Belt by Aluminum-26 Heating

Science ◽  
1993 ◽  
Vol 259 (5095) ◽  
pp. 653-655 ◽  
Author(s):  
Robert E. Grimm ◽  
Harry Y. McSween
Keyword(s):  
Thermal History ◽  
Solar Nebula ◽  
Planetary System ◽  
Asteroid Belt ◽  
The Sun ◽  
Initial Concentration ◽  
Decay Products ◽  
Spectral Class ◽  
Time Required ◽  
Electrical Induction

The dependence of asteroid spectral class (and inferred composition and thermal history) on heliocentric radius has been held to be the result of heating by a solar energy source, most likely electrical induction, during the formation of the planetary system. Such variations in thermal history can be more simply explained by the presence of different amounts of the radionuclide aluminum-26, whose decay products are observed in meteorites, in planetesimals. These differences occurred naturally as a function of the increasing amount of time required to aecrete objects farther from the sun, during which aluminum-26 decayed from its initial concentration in the solar nebula. Both theory and isotopic evidence suggest that increases in aecretion time across the asteroid belt are of order several half-lives of aluminum-26, which is sufficient to produce the inferred differences in thermal history.

scholarly journals Session I: Origin of the Solar Nebula

1971 ◽  
Vol 2 ◽  
pp. 195-203 ◽  
Author(s):  
F. Hoyle
Keyword(s):  
Angular Momentum ◽  
Solar Nebula ◽  
Planetary System ◽  
The Other ◽  
Chemical Compositions ◽  
The Sun ◽  
Second Line ◽  
Mass Fractions ◽  
The One ◽  
Solar Material

Prof. Fred L. Whipple kindly agreed to be the chairman for all three panels, and introduced the next speaker, Prof. F. Hoyle, who spoke on ‘The Solar Nebula’. Hoyle: I would like to begin this contribution by considering the deductions we can make by comparing the gross chemical compositions of the planets with the composition of the Sun. For this purpose I have divided the planets into the three groups shown inThe second line gives the mass fractions in the Sun of the major constituents of the planetary groups, while the fourth line gives the factors by which the present masses must be multiplied to give the amounts of solar material needed to yield the appropriate amounts of main planetary constituents. The interesting points emerge that Jupiter and Saturn require the least amount of solar material, and that Uranus and Neptune on the one hand and the terrestrial planets on the other require approximately equal amounts. The total requirement is for ≈10-2Mʘ This is less by a factor ≈10 than the amount postulated in many theories of the origin of the planetary system. However the amount we have now calculated can readily be seen to be consistent with angular momentum requirements.

The Infancy of Solar-Type Stars and its Relevance for the Origin of Life

1997 ◽  
Vol 161 ◽  
pp. 267-282 ◽  
Author(s):  
Thierry Montmerle
Keyword(s):  
Main Sequence ◽  
Solar Nebula ◽  
Circumstellar Disks ◽  
T Tauri Stars ◽  
Necessary Condition ◽  
Sequence Evolution ◽  
T Tauri ◽  
Solar Type ◽  
Optical Domain ◽  
The Origin Of Life

AbstractFor life to develop, planets are a necessary condition. Likewise, for planets to form, stars must be surrounded by circumstellar disks, at least some time during their pre-main sequence evolution. Much progress has been made recently in the study of young solar-like stars. In the optical domain, these stars are known as «T Tauri stars». A significant number show IR excess, and other phenomena indirectly suggesting the presence of circumstellar disks. The current wisdom is that there is an evolutionary sequence from protostars to T Tauri stars. This sequence is characterized by the initial presence of disks, with lifetimes ~ 1-10 Myr after the intial collapse of a dense envelope having given birth to a star. While they are present, about 30% of the disks have masses larger than the minimum solar nebula. Their disappearance may correspond to the growth of dust grains, followed by planetesimal and planet formation, but this is not yet demonstrated.

Annual gazetteer of planetary nomenclature, Intenationl astronomical union, working group for planetary system nomenclature

1986 ◽  
Author(s):  
Harold Masursky ◽  
Kaare Aksnes ◽  
G.E. Hunt ◽  
M.Y. Marov ◽  
P.M. Millman ◽  
...  
Keyword(s):  
Working Group ◽  
Planetary System

Drifting Through a Planetary System

2018 ◽  
Author(s):  
Karel Schrijver
Keyword(s):  
Seventeenth Century ◽  
Solar System ◽  
Virtual Worlds ◽  
Planetary System ◽  
System P ◽  
History Of ◽  
Or Team ◽  
Water Contents

This chapter describes how the first found exoplanets presented puzzles: they orbited where they should not have formed or where they could not have survived the death of their stars. The Solar System had its own puzzles to add: Mars is smaller than expected, while Venus, Earth, and Mars had more water—at least at one time—than could be understood. This chapter shows how astronomers worked through the combination of these puzzles: now we appreciate that planets can change their orbits, scatter water-bearing asteroids about, steal material from growing planets, or team up with other planets to stabilize their future. The special history of Jupiter and Saturn as a pair bringing both destruction and water to Earth emerged from the study of seventeenth-century resonant clocks, from the water contents of asteroids, and from experiments with supercomputers imposing the laws of physics on virtual worlds.

scholarly journals DESTINY: Database for the Effects of STellar encounters on dIsks and plaNetary sYstems

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Asmita Bhandare ◽  
Susanne Pfalzner
Keyword(s):  
Planetary System ◽  
Planetary Systems ◽  
Gravitational Effect ◽  
Parameter Study ◽  
Orbital Inclination ◽  
Particle Properties ◽  
Disk Size ◽  
Stellar Group ◽  
Cluster Environment ◽  
Parabolic Orbits

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.

scholarly journals GJ 436b and the stellar wind interaction: simulations constraints using Lyα and Hα transits

2020 ◽  
Author(s):  
Carolina Villarreal D’Angelo ◽  
Aline A Vidotto ◽  
Alejandro Esquivel ◽  
Gopal Hazra ◽  
Allison Youngblood
Keyword(s):  
Mass Loss ◽  
Stellar Wind ◽  
Planetary System ◽  
Neutral Hydrogen ◽  
Hydrogen Atmosphere ◽  
Planetary Atmosphere ◽  
Hydrodynamic Simulations ◽  
Stellar Disc ◽  
Planetary Mass ◽  
Best Fit

Abstract The GJ 436 planetary system is an extraordinary system. The Neptune-size planet that orbits the M3 dwarf revealed in the Lyα line an extended neutral hydrogen atmosphere. This material fills a comet-like tail that obscures the stellar disc for more than 10 hours after the planetary transit. Here, we carry out a series of 3D radiation hydrodynamic simulations to model the interaction of the stellar wind with the escaping planetary atmosphere. With these models, we seek to reproduce the $\sim 56\%$ absorption found in Lyα transits, simultaneously with the lack of absorption in Hα transit. Varying the stellar wind strength and the EUV stellar luminosity, we search for a set of parameters that best fit the observational data. Based on Lyα observations, we found a stellar wind velocity at the position of the planet to be around [250-460] km s−1 with a temperature of [3 − 4] × 105 K. The stellar and planetary mass loss rates are found to be 2 × 10−15 M⊙ yr−1 and ∼[6 − 10] × 109 g s−1, respectively, for a stellar EUV luminosity of [0.8 − 1.6] × 1027 erg s−1. For the parameters explored in our simulations, none of our models present any significant absorption in the Hα line in agreement with the observations.

scholarly journals III. On the nature and construction of the sun and fixed stars

1795 ◽  
Vol 85 ◽  
pp. 46-72 ◽  
Keyword(s):  
Central Body ◽  
Planetary System ◽  
Considerable Progress ◽  
The Sun ◽  
Great Satisfaction ◽  
The Earth ◽  
The World ◽  
Celestial Bodies ◽  
The Universe ◽  
Made In

Among the celestial bodies the sun is certainly the first which should attract our notice. It is a fountain of light that illuminates the world! it is the cause of that heat which main­tains the productive power of nature, and makes the earth a fit habitation for man! it is the central body of the planetary system; and what renders a knowledge of its nature still more interesting to us is, that the numberless stars which compose the universe, appear, by the strictest analogy, to be similar bodies. Their innate light is so intense, that it reaches the eye of the observer from the remotest regions of space, and forcibly claims his notice. Now, if we are convinced that an inquiry into the nature and properties of the sun is highly worthy of our notice, we may also with great satisfaction reflect on the considerable progress that has already been made in our knowledge of this eminent body. It would require a long detail to enumerate all the various discoveries which have been made on this subject; I shall, therefore, content myself with giving only the most capital of them.

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