DOI: 10.1016/j.epsl.2020.116694
论文题名: Evidence for post-nebula volatilisation in an exo-planetary body
作者: Harrison J.H.D. ; Shorttle O. ; Bonsor A.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 554 语种: 英语
中文关键词: exo-planetary bodies
; planetary volatile depletion
; polluted white dwarf stars
; post-nebula volatilisation
英文关键词: Extrasolar planets
; Moon
; Orbits
; Radioisotopes
; Abundance ratios
; Accreting materials
; Bulk compositions
; Planet formation
; Planetary bodies
; Planetary materials
; Short-lived radionuclides
; Volatile elements
; White dwarfs
; magma
; manganese
; planetary evolution
; radionuclide
; sodium
; solar system
; volatile element
; volatilization
英文摘要: The loss and gain of volatile elements during planet formation is key for setting their subsequent climate, geodynamics, and habitability. Two broad regimes of volatile element transport in and out of planetary building blocks have been identified: that occurring when the nebula is still present, and that occurring after it has dissipated. Evidence for volatile element loss in planetary bodies after the dissipation of the solar nebula is found in the high Mn to Na abundance ratio of Mars, the Moon, and many of the solar system's minor bodies. This volatile loss is expected to occur when the bodies are heated by planetary collisions and short-lived radionuclides, and enter a global magma ocean stage early in their history. The bulk composition of exo-planetary bodies can be determined by observing white dwarfs which have accreted planetary material. The abundances of Na, Mn, and Mg have been measured for the accreting material in four polluted white dwarf systems. Whilst the Mn/Na abundances of three white dwarf systems are consistent with the fractionations expected during nebula condensation, the high Mn/Na abundance ratio of GD362 means that it is not (>3σ). We find that heating of the planetary system orbiting GD362 during the star's giant branch evolution is insufficient to produce such a high Mn/Na. We, therefore, propose that volatile loss occurred in a manner analogous to that of the solar system bodies, either due to impacts shortly after their formation or from heating by short-lived radionuclides. We present potential evidence for a magma ocean stage on the exo-planetary body which currently pollutes the atmosphere of GD362. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165499
Appears in Collections: 气候变化与战略
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作者单位: Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA, United Kingdom; Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, United Kingdom
Recommended Citation:
Harrison J.H.D.,Shorttle O.,Bonsor A.. Evidence for post-nebula volatilisation in an exo-planetary body[J]. Earth and Planetary Science Letters,2021-01-01,554