Isotopic ratios D/H and ¹⁵ N/¹⁴N in giant planets

Marboeuf, Ulysse; Thiabaud, Amaury; Alibert, Yann; Benz, Willy (2018). Isotopic ratios D/H and ¹⁵ N/¹⁴N in giant planets. Monthly notices of the Royal Astronomical Society, 475(2), pp. 2355-2362. Oxford University Press 10.1093/mnras/stx3315

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The determination of isotopic ratios in planets is important since it allows us to investigate the origins and initial composition of materials. The present work aims to determine the possible range of values for isotopic ratios D/H and ¹⁵N/¹⁴N in giant planets. The main objective is to provide valuable theoretical assumptions on the isotopic composition of giant planets, their internal structure, and the main reservoirs of species. We use models of ice formation and planet formation that compute the composition of ices and gas accreted in the core and the envelope of planets. Assuming a single initial value for isotopic ratios in volatile species, and disruption of planetesimals in the envelope of gaseous planets, we obtain a wide variety of D/H and ¹⁵N/¹⁴N ratios in low-mass planets (≤100 Mearth) due to the migration pathway of planets, the accretion time of gas species whose relative abundance evolves with time, and isotope exchanges among species. If giant planets with mass greater than 100 Mearth have solar isotopic ratios such as Jupiter and Saturn due to their higher envelope mass, Neptune-type planets present values ranging between one and three times the solar value. It seems therefore difficult to use isotopic ratios in the envelope of these planets to get information about their formation in the disc. For giant planets, the ratios allow us to constrain the mass fraction of volatile species in the envelope needed to reproduce the observational data by assuming initial values for isotopic ratios in volatile species.

Item Type:

Journal Article (Original Article)


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 > Physics Institute
08 Faculty of Science > Physics Institute > NCCR PlanetS

UniBE Contributor:

Alibert, Yann Daniel Pierre, Benz, Willy


500 Science
500 Science > 520 Astronomy
500 Science > 530 Physics
600 Technology > 620 Engineering




Oxford University Press




Janine Jungo

Date Deposited:

18 Jun 2019 07:52

Last Modified:

05 Dec 2022 15:27

Publisher DOI:





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