Issue |
A&A
Volume 688, August 2024
|
|
---|---|---|
Article Number | A139 | |
Number of page(s) | 19 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/202346748 | |
Published online | 13 August 2024 |
A formation pathway for terrestrial planets with moderate water content involving atmospheric-volatile recycling
1
Heidelberger Institut für Theoretische Studien,
Schloss-Wolfsbrunnenweg 35,
69118
Heidelberg,
Germany
e-mail: jonas.mueller@h-its.org
2
Zentrum für Astronomie (ZAH/LSW), Heidelberg University,
Königstuhl 12,
69117
Heidelberg,
Germany
3
Department of Physics, University College Cork,
Cork,
Ireland
4
Max-Planck-Institut für Astronomie,
Königstuhl 17,
69117
Heidelberg,
Germany
5
Centre for ExoLife Sciences, Niels Bohr Institute,
Voldgade 5,
1350
Copenhagen,
Denmark
6
Instituut voor Sterrenkunde, KU Leuven,
Celestijnenlaan 200D,
3001
Leuven,
Belgium
Received:
26
April
2023
Accepted:
29
May
2024
Of the many recently discovered terrestrial exoplanets, some are expected to harbor moderate water mass fractions of a few percent. The formation pathways that can produce planets with these water mass fractions are not fully understood. Here, we use the code chemcomp, which consists of a semi-analytical 1D protoplanetary disk model harboring a migrating and accreting planet, to model the growth and composition of planets with moderate water mass fractions by pebble accretion in a protoplanetary disk around a TRAPPIST-1 analog star. This star is accompanied by seven terrestrial planets, of which the outer four planets likely contain water mass fractions of between 1% and 10%. We adopt a published model that considers the evaporation of pebbles in the planetary envelope, from where recycling flows can transport the volatile vapor back into the disk. We find that with this model, the planetary water content depends on the influx rate of pebbles onto the planet. A decreasing pebble influx with time reduces the envelope temperature and consequently allows the formation of planets with moderate water mass fractions as inferred for the outer TRAPPIST-1 planets for a number of different simulation configurations. This is further evidence that the recycling of vapor is an important component of planet formation needed to explain the vast and diverse population of exoplanets.
Key words: planets and satellites: atmospheres / planets and satellites: composition / planets and satellites: formation / protoplanetary disks
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This article is published in open access under the Subscribe to Open model. Subscribe to A&A to support open access publication.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.