BOWIE-ALIGN: how formation and migration histories of giant planets impact atmospheric compositions
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Published version
Author(s)
Type
Journal Article
Abstract
Hot Jupiters present a unique opportunity for measuring how planet formation history shapes present-day atmospheric composition. However, due to the myriad pathways influencing composition, a well-constructed sample of planets is needed to determine whether formation history can be accurately traced back from atmospheric composition. To this end, the BOWIE-ALIGN survey will compare the compositions of 8 hot Jupiters around F stars, 4 with orbits aligned with the stellar rotation axis and 4 misaligned. Using the alignment as an indicator for planets that underwent disc migration or high-eccentricity migration, one can determine whether migration history produces notable differences in composition between the two samples of planets. This paper describes the planet formation model that motivates our observing programme. Our model traces the accretion of chemical components from the gas and dust in the disc over a broad parameter space to create a full, unbiased model sample from which we can estimate the range of final atmospheric compositions. For high metallicity atmospheres (O/H ≥ 10 × solar), the C/O ratios of aligned and misaligned planets diverge, with aligned planets having lower C/O (<0.25) due to the accretion of oxygen-rich silicates from the inner disc. However, silicates may rain out instead of releasing their oxygen into the atmosphere. This would significantly increase the C/O of aligned planets (C/O >0.6), inverting the trend between the aligned and misaligned planets. Nevertheless, by comparing statistically significant samples of aligned and misaligned planets, we expect atmospheric composition to constrain how planets form.
Date Issued
2024-11
Date Acceptance
2024-10-01
Citation
Monthly Notices of the Royal Astronomical Society, 2024, 535 (1), pp.171-186
ISSN
0035-8711
Publisher
Oxford University Press
Start Page
171
End Page
186
Journal / Book Title
Monthly Notices of the Royal Astronomical Society
Volume
535
Issue
1
Copyright Statement
© The Author(s) 2024. Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article
distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits
unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits
unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
Identifier
http://dx.doi.org/10.1093/mnras/stae2362
Publication Status
Published
Date Publish Online
2024-10-15