From stellar nebula to planets: The refractory components

Thiabaud, Amaury; Marboeuf, Ulysse; Alibert, Yann; Cabral, Nahuel; Leya, Ingo; Mezger, Klaus (2014). From stellar nebula to planets: The refractory components. Astronomy and astrophysics, 562(A27), A27. EDP Sciences 10.1051/0004-6361/201322208

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Context. To date, calculations of planet formation have mainly focused on dynamics, and only a few have considered the chemical composition of refractory elements and compounds in the planetary bodies. While many studies have been concentrating on the chemical composition of volatile compounds (such as H2O, CO, CO2) incorporated in planets, only a few have considered the refractory materials as well, although they are of great importance for the formation of rocky planets. Aims. We computed the abundance of refractory elements in planetary bodies formed in stellar systems with a solar chemical composition by combining models of chemical composition and planet formation. We also considered the formation of refractory organic compounds, which have been ignored in previous studies on this topic. Methods. We used the commercial software package HSC Chemistry to compute the condensation sequence and chemical composition of refractory minerals incorporated into planets. The problem of refractory organic material is approached with two distinct model calculations: the first considers that the fraction of atoms used in the formation of organic compounds is removed from the system (i.e., organic compounds are formed in the gas phase and are non-reactive); and the second assumes that organic compounds are formed by the reaction between different compounds that had previously condensed from the gas phase. Results. Results show that refractory material represents more than 50 wt % of the mass of solids accreted by the simulated planets with up to 30 wt % of the total mass composed of refractory organic compounds. Carbide and silicate abundances are consistent with C/O and Mg/Si elemental ratios of 0.5 and 1.02 for the Sun. Less than 1 wt % of carbides are present in the planets, and pyroxene and olivine are formed in similar quantities. The model predicts planets that are similar in composition to those of the solar system. Starting from a common initial nebula composition, it also shows that a wide variety of chemically different planets can form, which means that the differences in planetary compositions are due to differences in the planetary formation process. Conclusions. We show that a model in which refractory organic material is absent from the system is more compatible with observations. The use of a planet formation model is essential to form a wide diversity of planets in a consistent way.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences > Theoretical Astrophysics and Planetary Science (TAPS)
08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences
08 Faculty of Science > Institute of Geological Sciences
08 Faculty of Science > Institute of Geological Sciences > Isotope Geology
10 Strategic Research Centers > Center for Space and Habitability (CSH)

UniBE Contributor:

Thiabaud, Amaury; Marboeuf, Ulysse; Alibert, Yann; Cabral, Nahuel; Leya, Ingo and Mezger, Klaus

Subjects:

500 Science > 550 Earth sciences & geology
500 Science > 520 Astronomy
600 Technology > 620 Engineering

ISSN:

0004-6361

Publisher:

EDP Sciences

Language:

English

Submitter:

Klaus Mezger

Date Deposited:

09 Jan 2015 08:27

Last Modified:

02 Sep 2016 12:25

Publisher DOI:

10.1051/0004-6361/201322208

Uncontrolled Keywords:

planets and satellites: composition / astrochemistry / planets and satellites: formation

BORIS DOI:

10.7892/boris.61440

URI:

https://boris.unibe.ch/id/eprint/61440

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