TY - JOUR
T1 - New insights on Saturn's formation from its nitrogen isotopic composition
AU - Mousis, Olivier
AU - Lunine, Jonathan I.
AU - Fletcher, Leigh N.
AU - Mandt, Kathleen E.
AU - Ali-Dib, Mohamad
AU - Gautier, Daniel
AU - Atreya, Sushil
N1 - Publisher Copyright:
© 2014. The American Astronomical Society. All rights reserved.
PY - 2014/12/1
Y1 - 2014/12/1
N2 - The recent derivation of a lower limit for the 14N/15N ratio in Saturn's ammonia, which is found to be consistent with the Jovian value, prompted us to revise models of Saturn's formation using as constraints the supersolar abundances of heavy elements measured in its atmosphere. Here we find that it is possible to account for both Saturn's chemical and isotopic compositions if one assumes the formation of its building blocks at ∼45 K in the protosolar nebula, provided that the O abundance was ∼2.6 times protosolar in its feeding zone. To do so, we used a statistical thermodynamic model to investigate the composition of the clathrate phase that formed during the cooling of the protosolar nebula and from which the building blocks of Saturn were agglomerated. We find that Saturn's O/H is at least ∼34.9 times protosolar and that the corresponding mass of heavy elements (∼43.1 M⊕) is within the range predicted by semi-convective interior models.
AB - The recent derivation of a lower limit for the 14N/15N ratio in Saturn's ammonia, which is found to be consistent with the Jovian value, prompted us to revise models of Saturn's formation using as constraints the supersolar abundances of heavy elements measured in its atmosphere. Here we find that it is possible to account for both Saturn's chemical and isotopic compositions if one assumes the formation of its building blocks at ∼45 K in the protosolar nebula, provided that the O abundance was ∼2.6 times protosolar in its feeding zone. To do so, we used a statistical thermodynamic model to investigate the composition of the clathrate phase that formed during the cooling of the protosolar nebula and from which the building blocks of Saturn were agglomerated. We find that Saturn's O/H is at least ∼34.9 times protosolar and that the corresponding mass of heavy elements (∼43.1 M⊕) is within the range predicted by semi-convective interior models.
KW - Planets and satellites: Atmospheres
KW - Planets and satellites: Composition
KW - Planets and satellites: Formation
KW - Planets and satellites: Individual (saturn)
KW - Protoplanetary disks
KW - Solid state: Volatile
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U2 - 10.1088/2041-8205/796/2/L28
DO - 10.1088/2041-8205/796/2/L28
M3 - Article
AN - SCOPUS:84911916675
SN - 2041-8205
VL - 796
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L28
ER -