The Astrophysical Journal Letters (Jan 2024)
New Mass and Radius Constraints on the LHS 1140 Planets: LHS 1140 b Is either a Temperate Mini-Neptune or a Water World
- Charles Cadieux,
- Mykhaylo Plotnykov,
- René Doyon,
- Diana Valencia,
- Farbod Jahandar,
- Lisa Dang,
- Martin Turbet,
- Thomas J. Fauchez,
- Ryan Cloutier,
- Collin Cherubim,
- Étienne Artigau,
- Neil J. Cook,
- Billy Edwards,
- Tim Hallatt,
- Benjamin Charnay,
- François Bouchy,
- Romain Allart,
- Lucile Mignon,
- Frédérique Baron,
- Susana C. C. Barros,
- Björn Benneke,
- B. L. Canto Martins,
- Nicolas B. Cowan,
- J. R. De Medeiros,
- Xavier Delfosse,
- Elisa Delgado-Mena,
- Xavier Dumusque,
- David Ehrenreich,
- Yolanda G. C. Frensch,
- J. I. González Hernández,
- Nathan C. Hara,
- David Lafrenière,
- Gaspare Lo Curto,
- Lison Malo,
- Claudio Melo,
- Dany Mounzer,
- Vera Maria Passeger,
- Francesco Pepe,
- Anne-Sophie Poulin-Girard,
- Nuno C. Santos,
- Danuta Sosnowska,
- Alejandro Suárez Mascareño,
- Simon Thibault,
- Valentina Vaulato,
- Gregg A. Wade,
- François Wildi
Affiliations
- Charles Cadieux
- ORCiD
- Institut Trottier de recherche sur les exoplanètes, Université de Montréal , 1375 Ave Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada ; [email protected]
- Mykhaylo Plotnykov
- ORCiD
- Department of Physics, University of Toronto , Toronto, ON M5S 3H4, Canada
- René Doyon
- ORCiD
- Institut Trottier de recherche sur les exoplanètes, Université de Montréal , 1375 Ave Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada ; [email protected]; Observatoire du Mont-Mégantic, Université de Montréal , Montréal, QC H3C 3J7, Canada
- Diana Valencia
- ORCiD
- Department of Physical & Environmental Sciences, University of Toronto at Scarborough , Toronto, ON M1C 1A4, Canada; David A. Dunlap Department of Astronomy & Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4, Canada
- Farbod Jahandar
- ORCiD
- Institut Trottier de recherche sur les exoplanètes, Université de Montréal , 1375 Ave Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada ; [email protected]
- Lisa Dang
- ORCiD
- Institut Trottier de recherche sur les exoplanètes, Université de Montréal , 1375 Ave Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada ; [email protected]
- Martin Turbet
- ORCiD
- Laboratoire de Météorologie Dynamique/IPSL, CNRS, Sorbonne Université , Ecole Normale Supérieure, PSL Research University, Ecole Polytechnique, F-75005 Paris, France; Laboratoire d’astrophysique de Bordeaux, Univ. Bordeaux , CNRS, B18N, allée Geoffroy Saint-Hilaire, F-33615 Pessac, France
- Thomas J. Fauchez
- ORCiD
- NASA Goddard Space Flight Center , 8800 Greenbelt Road, Greenbelt, MD 20771, USA; Integrated Space Science and Technology Institute, Department of Physics, American University , Washington, DC, USA; NASA GSFC Sellers Exoplanet Environments Collaboration , 8800 Greenbelt Road, Greenbelt, MD 20771, USA
- Ryan Cloutier
- ORCiD
- Department of Physics & Astronomy, McMaster University , 1280 Main Street West, Hamilton, ON L8S 4L8, Canada
- Collin Cherubim
- ORCiD
- Earth and Planetary Science, Harvard University , 20 Oxford Street, Cambridge, MA 02138, USA; Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA
- Étienne Artigau
- ORCiD
- Institut Trottier de recherche sur les exoplanètes, Université de Montréal , 1375 Ave Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada ; [email protected]; Observatoire du Mont-Mégantic, Université de Montréal , Montréal, QC H3C 3J7, Canada
- Neil J. Cook
- ORCiD
- Institut Trottier de recherche sur les exoplanètes, Université de Montréal , 1375 Ave Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada ; [email protected]
- Billy Edwards
- ORCiD
- SRON, Netherlands Institute for Space Research , Niels Bohrweg 4, NL-2333 CA, Leiden, The Netherlands; Department of Physics and Astronomy, University College London , London, UK
- Tim Hallatt
- ORCiD
- Institut Trottier de recherche sur les exoplanètes, Université de Montréal , 1375 Ave Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada ; [email protected]; Department of Physics and Trottier Space Institute, McGill University , Montréal, QC H3A 2T8, Canada
- Benjamin Charnay
- ORCiD
- LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université , Université Paris-Cité, 5 place Jules Janssen, F-92195 Meudon, France
- François Bouchy
- ORCiD
- Departement d’astronomie, Université de Genève , Chemin Pegasi, 51, CH-1290 Versoix, Switzerland
- Romain Allart
- ORCiD
- Institut Trottier de recherche sur les exoplanètes, Université de Montréal , 1375 Ave Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada ; [email protected]
- Lucile Mignon
- ORCiD
- Departement d’astronomie, Université de Genève , Chemin Pegasi, 51, CH-1290 Versoix, Switzerland
- Frédérique Baron
- ORCiD
- Institut Trottier de recherche sur les exoplanètes, Université de Montréal , 1375 Ave Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada ; [email protected]
- Susana C. C. Barros
- ORCiD
- Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto , CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal; Departamento de Fisica e Astronomia, Faculdade de Ciencias, Universidade do Porto, Rua Campo Alegre , 4169-007 Porto, Portugal
- Björn Benneke
- ORCiD
- Institut Trottier de recherche sur les exoplanètes, Université de Montréal , 1375 Ave Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada ; [email protected]
- B. L. Canto Martins
- ORCiD
- Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte , Campus Universitário, Natal, RN, 59072-970, Brazil
- Nicolas B. Cowan
- ORCiD
- Department of Physics and Trottier Space Institute, McGill University , Montréal, QC H3A 2T8, Canada; Department of Earth & Planetary Sciences, McGill University , 3450 rue University, Montréal, QC H3A 0E8, Canada
- J. R. De Medeiros
- ORCiD
- Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte , Campus Universitário, Natal, RN, 59072-970, Brazil
- Xavier Delfosse
- ORCiD
- Univ. Grenoble Alpes , CNRS, IPAG, F-38000 Grenoble, France
- Elisa Delgado-Mena
- ORCiD
- Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto , CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal
- Xavier Dumusque
- ORCiD
- Departement d’astronomie, Université de Genève , Chemin Pegasi, 51, CH-1290 Versoix, Switzerland
- David Ehrenreich
- ORCiD
- Departement d’astronomie, Université de Genève , Chemin Pegasi, 51, CH-1290 Versoix, Switzerland
- Yolanda G. C. Frensch
- ORCiD
- Departement d’astronomie, Université de Genève , Chemin Pegasi, 51, CH-1290 Versoix, Switzerland
- J. I. González Hernández
- ORCiD
- Instituto de Astrofísica de Canarias , E-38205 La Laguna, Tenerife, Spain; Departamento de Astrofísica, Universidad de La Laguna , E-38206 La Laguna, Tenerife, Spain
- Nathan C. Hara
- ORCiD
- Departement d’astronomie, Université de Genève , Chemin Pegasi, 51, CH-1290 Versoix, Switzerland
- David Lafrenière
- ORCiD
- Institut Trottier de recherche sur les exoplanètes, Université de Montréal , 1375 Ave Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada ; [email protected]
- Gaspare Lo Curto
- ORCiD
- European Southern Observatory , Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany
- Lison Malo
- ORCiD
- Institut Trottier de recherche sur les exoplanètes, Université de Montréal , 1375 Ave Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3, Canada ; [email protected]; Observatoire du Mont-Mégantic, Université de Montréal , Montréal, QC H3C 3J7, Canada
- Claudio Melo
- ORCiD
- European Southern Observatory , Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany
- Dany Mounzer
- ORCiD
- Departement d’astronomie, Université de Genève , Chemin Pegasi, 51, CH-1290 Versoix, Switzerland
- Vera Maria Passeger
- ORCiD
- Instituto de Astrofísica de Canarias , E-38205 La Laguna, Tenerife, Spain; Departamento de Astrofísica, Universidad de La Laguna , E-38206 La Laguna, Tenerife, Spain; Hamburger Sternwarte , Gojenbergsweg 112, D-21029 Hamburg, Germany
- Francesco Pepe
- ORCiD
- Departement d’astronomie, Université de Genève , Chemin Pegasi, 51, CH-1290 Versoix, Switzerland
- Anne-Sophie Poulin-Girard
- ABB, Québec, G1P 0B2, Canada
- Nuno C. Santos
- ORCiD
- Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto , CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal; Departamento de Fisica e Astronomia, Faculdade de Ciencias, Universidade do Porto, Rua Campo Alegre , 4169-007 Porto, Portugal
- Danuta Sosnowska
- Departement d’astronomie, Université de Genève , Chemin Pegasi, 51, CH-1290 Versoix, Switzerland
- Alejandro Suárez Mascareño
- ORCiD
- Instituto de Astrofísica de Canarias , E-38205 La Laguna, Tenerife, Spain; Departamento de Astrofísica, Universidad de La Laguna , E-38206 La Laguna, Tenerife, Spain
- Simon Thibault
- ORCiD
- Centre d’optique, photonique et lasers, Université Laval , Québec, G1V 0A6, Canada
- Valentina Vaulato
- ORCiD
- Departement d’astronomie, Université de Genève , Chemin Pegasi, 51, CH-1290 Versoix, Switzerland
- Gregg A. Wade
- ORCiD
- Department of Physics and Space Science, Royal Military College of Canada , P.O. Box 17000, Station Forces, Kingston, ON, Canada
- François Wildi
- ORCiD
- Departement d’astronomie, Université de Genève , Chemin Pegasi, 51, CH-1290 Versoix, Switzerland
- DOI
- https://doi.org/10.3847/2041-8213/ad1691
- Journal volume & issue
-
Vol. 960,
no. 1
p. L3
Abstract
The two-planet transiting system LHS 1140 has been extensively observed since its discovery in 2017, notably with Spitzer, HST, TESS, and ESPRESSO, placing strong constraints on the parameters of the M4.5 host star and its small temperate exoplanets, LHS 1140 b and c. Here, we reanalyze the ESPRESSO observations of LHS 1140 with the novel line-by-line framework designed to fully exploit the radial velocity content of a stellar spectrum while being resilient to outlier measurements. The improved radial velocities, combined with updated stellar parameters, consolidate our knowledge of the mass of LHS 1140 b (5.60 ± 0.19 M _⊕ ) and LHS 1140 c (1.91 ± 0.06 M _⊕ ) with an unprecedented precision of 3%. Transits from Spitzer, HST, and TESS are jointly analyzed for the first time, allowing us to refine the planetary radii of b (1.730 ± 0.025 R _⊕ ) and c (1.272 ± 0.026 R _⊕ ). Stellar abundance measurements of refractory elements (Fe, Mg, and Si) obtained with NIRPS are used to constrain the internal structure of LHS 1140 b. This planet is unlikely to be a rocky super-Earth, as previously reported, but rather a mini-Neptune with a ∼0.1% H/He envelope by mass or a water world with a water-mass fraction between 9% and 19%, depending on the atmospheric composition and relative abundance of Fe and Mg. While the mini-Neptune case would not be habitable, a water-abundant LHS 1140 b potentially has habitable surface conditions according to 3D global climate models, suggesting liquid water at the substellar point for atmospheres with relatively low CO _2 concentration, from Earth-like to a few bars.
Keywords
