Extreme Water Loss and Abiotic O$_2$ Buildup On Planets Throughout the Habitable Zones of M Dwarfs
Rodrigo Luger,Rory Barnes +1 more
TLDR
In this paper, it was shown that the amount of water lost scales with the planet mass, since the diffusion-limited hydrogen escape flux is proportional to the planet surface gravity, leading to the loss of several Earth oceans of water from planets throughout the habitable zone.Abstract:
We show that terrestrial planets in the habitable zones of M dwarfs older than $\sim$ 1 Gyr could have been in runaway greenhouses for several hundred Myr following their formation due to the star's extended pre-main sequence phase, provided they form with abundant surface water. Such prolonged runaway greenhouses can lead to planetary evolution divergent from that of Earth. During this early runaway phase, photolysis of water vapor and hydrogen/oxygen escape to space can lead to the loss of several Earth oceans of water from planets throughout the habitable zone, regardless of whether the escape is energy-limited or diffusion-limited. We find that the amount of water lost scales with the planet mass, since the diffusion-limited hydrogen escape flux is proportional to the planet surface gravity. In addition to undergoing potential desiccation, planets with inefficient oxygen sinks at the surface may build up hundreds to thousands of bars of abiotically produced O$_2$, resulting in potential false positives for life. The amount of O$_2$ that builds up also scales with the planet mass; we find that O$_2$ builds up at a constant rate that is controlled by diffusion: $\sim$ 5 bars/Myr on Earth-mass planets and up to $\sim$ 25 bars/Myr on super-Earths. As a result, some recently discovered super-Earths in the habitable zone such as GJ 667Cc could have built up as many as 2000 bars of O$_2$ due to the loss of up to 10 Earth oceans of water. The fate of a given planet strongly depends on the extreme ultraviolet flux, the duration of the runaway regime, the initial water content, and the rate at which oxygen is absorbed by the surface. In general, we find that the initial phase of high luminosity may compromise the habitability of many terrestrial planets orbiting low mass stars.read more
Citations
More filters
Journal ArticleDOI
Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
Michaël Gillon,Amaury H. M. J. Triaud,Brice-Olivier Demory,Emmanuel Jehin,Eric Agol,Katherine M. Deck,Susan M. Lederer,Julien de Wit,Artem Burdanov,James G. Ingalls,Emeline Bolmont,Jérémy Leconte,Sean N. Raymond,Franck Selsis,Martin Turbet,Khalid Barkaoui,Adam J. Burgasser,Matthew R. Burleigh,Sean Carey,Aleksander Chaushev,Chris M. Copperwheat,Laetitia Delrez,Catarina S. Fernandes,Daniel Luke Holdsworth,Enrico J. Kotze,Valérie Van Grootel,Y. Almleaky,Zouhair Benkhaldoun,Pierre Magain,Didier Queloz +29 more
TL;DR: The observations reveal that at least seven planets with sizes and masses similar to those of Earth revolve around TRAPPIST-1, and the six inner planets form a near-resonant chain, such that their orbital periods are near-ratios of small integers.
Journal ArticleDOI
A temperate rocky super-Earth transiting a nearby cool star
Jason A. Dittmann,Jonathan Irwin,David Charbonneau,Xavier Bonfils,Xavier Bonfils,Nicola Astudillo-Defru,Raphaëlle D. Haywood,Zachory K. Berta-Thompson,Elisabeth R. Newton,Joseph E. Rodriguez,Jennifer G. Winters,Thiam-Guan Tan,J. M. Almenara,J. M. Almenara,J. M. Almenara,François Bouchy,X. Delfosse,X. Delfosse,T. Forveille,T. Forveille,Christophe Lovis,Felipe Murgas,Felipe Murgas,Felipe Murgas,Francesco Pepe,Nuno C. Santos,Stéphane Udry,A. Wunsche,A. Wunsche,Gilbert A. Esquerdo,David W. Latham,Courtney D. Dressing +31 more
TL;DR: Observations of LHS 1140b, a planet with a radius of 1.4 Earth radii transiting a small, cool star (L HS 1140) 12 parsecs away, measure the mass of the planet to be 6.6 times that of Earth, consistent with a rocky bulk composition, and place an upper limit on the orbital eccentricity.
Journal ArticleDOI
The habitability of planets orbiting M-dwarf stars
TL;DR: A comprehensive review of the current knowledge of M-dwarf planet occurrence and habitability based on work done in this area over the past decade, and summarize future directions planned in this quickly evolving field is provided in this article.
Journal ArticleDOI
A seven-planet resonant chain in TRAPPIST-1
Rodrigo Luger,Marko Sestovic,Ethan Kruse,Simon L. Grimm,Brice-Olivier Demory,Eric Agol,Emeline Bolmont,Daniel C. Fabrycky,Catarina Silva Fernandes,Valérie Van Grootel,Adam J. Burgasser,Michaël Gillon,James G. Ingalls,Emmanuel Jehin,Sean N. Raymond,Franck Selsis,Amaury H. M. J. Triaud,Thomas Barclay,Geert Barentsen,Steve B. Howell,Laetitia Delrez,Julien de Wit,Daniel Foreman-Mackey,Daniel Luke Holdsworth,Jérémy Leconte,Susan M. Lederer,Martin Turbet,Y. Almleaky,Zouhair Benkhaldoun,Pierre Magain,Brett M. Morris,Kevin Heng,Didier Queloz +32 more
TL;DR: The TRAPPIST-1 system is the first transiting planet system found orbiting an ultra-cool dwarf star as mentioned in this paper, which was unconstrained until now, and has a radius of 0.715 Earth radii and an equilibrium temperature of 169 K, placing it at the snow line.
Journal ArticleDOI
A rocky planet transiting a nearby low-mass star
Zachory K. Berta-Thompson,Jonathan Irwin,David Charbonneau,Elisabeth R. Newton,Jason A. Dittmann,Nicola Astudillo-Defru,Xavier Bonfils,Michaël Gillon,Emmanuel Jehin,Antony A. Stark,B. Stalder,Francois Bouchy,Xavier Delfosse,Thierry Forveille,Christophe Lovis,Michel Mayor,V. Neves,Francesco Pepe,Nuno C. Santos,Stéphane Udry,A. Wunsche +20 more
TL;DR: In this paper, the authors reported observations of GJ 1132b, a planet with a size of 1.2 Earth radii that is transiting a small star 12 parsecs away.
References
More filters
Book
New light on dark stars
I. Neill Reid,Suzanne L. Hawley +1 more
TL;DR: In this paper, a coal-shale interface detector for use with coal cutting equipment consisting of a reciprocating hammer having an accelerometer mounted thereon to measure the impact of the hammer as it penetrates the ceiling or floor surface of a mine.
Related Papers (5)
Extreme Water Loss and Abiotic O2 Buildup on Planets Throughout the Habitable Zones of M Dwarfs
Rodrigo Luger,Rory Barnes +1 more
Habitable zones around main sequence stars
Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
Michaël Gillon,Amaury H. M. J. Triaud,Brice-Olivier Demory,Emmanuel Jehin,Eric Agol,Katherine M. Deck,Susan M. Lederer,Julien de Wit,Artem Burdanov,James G. Ingalls,Emeline Bolmont,Jérémy Leconte,Sean N. Raymond,Franck Selsis,Martin Turbet,Khalid Barkaoui,Adam J. Burgasser,Matthew R. Burleigh,Sean Carey,Aleksander Chaushev,Chris M. Copperwheat,Laetitia Delrez,Catarina S. Fernandes,Daniel Luke Holdsworth,Enrico J. Kotze,Valérie Van Grootel,Y. Almleaky,Zouhair Benkhaldoun,Pierre Magain,Didier Queloz +29 more
A terrestrial planet candidate in a temperate orbit around Proxima Centauri
Guillem Anglada-Escudé,Pedro J. Amado,John R. Barnes,Z. M. Berdiñas,R. Paul Butler,Gavin A. L. Coleman,Ignacio de la Cueva,Stefan Dreizler,Michael Endl,Benjamin Giesers,Sandra V. Jeffers,James S. Jenkins,Hugh R. A. Jones,Marcin Kiraga,Martin Kürster,Marίa J. López-González,Christopher Marvin,Nicolás Morales,Julien Morin,Richard P. Nelson,Jose Luis Ortiz,Aviv Ofir,Sijme-Jan Paardekooper,Ansgar Reiners,E. Rodriguez,Cristina Rodrίguez-López,L. F. Sarmiento,J. B. P. Strachan,Yiannis Tsapras,Mikko Tuomi,Mathias Zechmeister +30 more