History and Habitability of the LP 890-9 Planetary System
Journal article, 2025
We present numerous aspects of the evolution of the LP 890-9 (SPECULOOS-2/TOI-4306) planetary system, focusing on the likelihood that planet c can support life. We find that the host star reaches the main sequence in 1 Gyr and that planet c lies close to the inner boundary of the habitable zone. We find the magma ocean stage can last up to 50 Myr, remove eight Earth oceans of water, and leave up to 2000 bars of oxygen in the atmosphere. However, if the planet forms with a hydrogen envelope as small as 0.1 Earth masses, no water will be lost during the star's pre-main-sequence phase from thermal escape processes. We find that the planets are unlikely to be in a 3:1 mean motion resonance and that both planets tidally circularize within 0.5 Gyr when tidal dissipation is held constant. However, if tidal dissipation is a function of mantle temperature and rheology, then we find that planet c's orbit may require more than 7 Gyr to circularize, during which time tidal heating may reach hundreds of terawatts. We thus conclude that the habitability of planet c depends most strongly on the initial volatile content and internal properties, but no data yet preclude the viability of an active biosphere on the planet.
Author
Rory Barnes
University of Washington
Laura N. R. do Amaral
Consortium on Habitability and Atmospheres of M-dwarf Planets (CHAMPs)
Arizona State University
Universidad Nacional Autónoma de México
National Aeronautics and Space Administration (NASA)
Jessica Birky
University of Washington
Ludmila Carone
University of St Andrews
Austrian Academy of Sciences
Peter Driscoll
Carnegie Institution for Science
Joseph R. Livesey
University of Washington
University of Wisconsin Madison
David Graham
Heidelberg University
Juliette Becker
California Institute of Technology (Caltech)
University of Wisconsin Madison
Kaiming Cui
Shanghai Jiao Tong University
Martin Schlecker
University of Arizona
Rodolfo Garcia
University of Washington
Megan Gialluca
University of Washington
Arthur Adams
University of California at Riverside
M. D. Redyan Ahmed
Indian Institute of Science Education & Research (IISER)
Paul Bonney
University of Arkansas System
Wynter Broussard
University of California at Riverside
Mario Damasso
Istituto nazionale di astrofisica (INAF)
William C. Danchi
National Aeronautics and Space Administration (NASA)
Russell Deitrick
University of Victoria
Elsa Ducrot
Paris Descartes University
Emeline F. Fromont
University of Maryland
Brandt Gaches
The University of Texas at Austin
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Sakshi Gupta
Indian Institute of Science Education & Research (IISER)
Michelle L. Hill
University of California at Riverside
James A. G. Jackman
Arizona State University
Estelle M. Janin
Arizona State University
Mikolaj Karawacki
Nicolaus Copernicus University
Matheus Daniel Koren
Federal University of Rio Grande do Norte
Michaela Leung
University of California at Riverside
Arturo Miranda-Rosete
Universidad Nacional Autónoma de México
Michael Kent A. Olohoy
Rizal Technological University
Cecelia Ngo
University of California at Riverside
Daria Paul
University of Cologne
Chandan Kumar Sahu
National Institute of Science Education and Research
Mohammad Afzal Shadab
The University of Texas at Austin
Princeton University
Edward W. Schwieterman
University of California at Riverside
Katie Texeira
The University of Texas at Austin
Allona Vazan
Open University of Israel
Karen N. Delgado Delgado Vega
University of Puerto Rico at Arecibo (UPRA)
Rohit Vijayakumar
Indian Institute of Science
Jonathan T. Wojack
University of Southern Queensland
Planetary Science Journal
26323338 (eISSN)
Vol. 6 1 25Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.3847/PSJ/ad94dc