Astronomy and Astrophysics; Space and Planetary Science
Abstract :
[en] We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT 3780 (TIC 36724087, TOI-732, V = 13.07, K s = 8.204, R s = 0.374 R o˙, M s = 0.401 M o˙, d = 22 pc). The two planet candidates are identified in a single Transiting Exoplanet Survey Satellite sector and validated with reconnaissance spectroscopy, ground-based photometric follow-up, and high-resolution imaging. With measured orbital periods of P b = 0.77, P c = 12.25 days and sizes r p,b = 1.33 ± 0.07, r p,c = 2.30 ± 0.16 R ⊕, the two planets span the radius valley in period-radius space around low-mass stars, thus making the system a laboratory to test competing theories of the emergence of the radius valley in that stellar mass regime. By combining 63 precise radial velocity measurements from the High Accuracy Radial velocity Planet Searcher (HARPS) and HARPS-N, we measure planet masses of mpb 2.62+ 0.48 and-0.46= mpc 8.6+1.6-1.3 M⊕, which indicates that LTT 3780b has a bulk composition consistent with being Earth-like, while LTT 3780c likely hosts an extended H/He envelope. We show that the recovered planetary masses are consistent with predictions from both photoevaporation and core-powered mass-loss models. The brightness and small size of LTT 3780, along with the measured planetary parameters, render LTT 3780b and c as accessible targets for atmospheric characterization of planets within the same planetary system and spanning the radius valley.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Cloutier, Ryan ; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Eastman, Jason D. ; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Rodriguez, Joseph E. ; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Astudillo-Defru, Nicola; Departamento de Matemática y Física Aplicadas, Universidad Católica de la Santísima Concepción, Concepción, Chile
Bonfils, Xavier; CNRS, IPAG, France
Mortier, Annelies ; Astrophysics Group, Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
Watson, Christopher A.; Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast, United Kingdom
Stalport, Manu ; Université de Liège - ULiège > Unités de recherche interfacultaires > Space sciences, Technologies and Astrophysics Research (STAR) ; Observatoire Astronomique de l'Université de Gen ve, Versoix, Switzerland
Pinamonti, Matteo ; INAF-Osservatorio Astrofisico di Torino, Strada Osservatorio 20, Pino Torinese (To), Italy
Lienhard, Florian ; Astrophysics Group, Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
Harutyunyan, Avet; Fundación Galileo Galilei-INAF, Rambla José Ana Fernandez Pérez 7, Breña Baja, Spain
Damasso, Mario; INAF-Osservatorio Astrofisico di Torino, Strada Osservatorio 20, Pino Torinese (To), Italy
Latham, David W. ; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Collins, Karen A. ; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Massey, Robert ; American Association of Variable Star Observers (AAVSO), Cambridge, United States
Irwin, Jonathan; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Winters, Jennifer G. ; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Charbonneau, David ; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Ziegler, Carl ; Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto, Canada
Matthews, Elisabeth ; Department of Earth, Atmospheric and Planetary Sciences and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, United States
Crossfield, Ian J. M.; Department of Physics and Astronomy, University of Kansas, Lawrence, United States
Kreidberg, Laura ; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Quinn, Samuel N. ; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Ricker, George ; Department of Earth, Atmospheric and Planetary Sciences and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, United States
Vanderspek, Roland ; Department of Earth, Atmospheric and Planetary Sciences and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, United States
Seager, Sara ; Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, United States ; Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, United States ; Department of Aeronautics and Astronautics, MIT, Cambridge, United States
Winn, Joshua ; Department of Astrophysical Sciences, Princeton University, Princeton, United States
Jenkins, Jon M. ; NASA Ames Research Center, Moffett Field, United States
Vezie, Michael; Department of Earth, Atmospheric and Planetary Sciences and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, United States
Udry, Stéphane ; Observatoire Astronomique de l'Université de Gen ve, Versoix, Switzerland
Twicken, Joseph D. ; NASA Ames Research Center, Moffett Field, United States ; SETI Institute, Mountain View, United States
Tenenbaum, Peter ; NASA Ames Research Center, Moffett Field, United States
Sozzetti, Alessandro ; INAF-Osservatorio Astrofisico di Torino, Strada Osservatorio 20, Pino Torinese (To), Italy
Ségransan, Damien ; Observatoire Astronomique de l'Université de Gen ve, Versoix, Switzerland
Schlieder, Joshua E. ; NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, United States
Sasselov, Dimitar ; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Santos, Nuno C. ; Instituto de Astrofísica e Ciencias do Espa o, Universidade do Porto CAUP, Rua das Estrelas, Porto, Portugal ; Departamento de Física e Astronomia, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, Porto, Portugal
Rice, Ken; SUPA, Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh, United Kingdom
Rackham, Benjamin V. ; Department of Earth, Atmospheric and Planetary Sciences and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, United States
Poretti, Ennio ; Fundación Galileo Galilei-INAF, Rambla José Ana Fernandez Pérez 7, Breña Baja, Spain ; INAF-Osservatorio Astronomico di Brera, Merate, Italy
Piotto, Giampaolo ; Dip. di Fisica e Astronomia Galileo Galilei-Universit di Padova, Vicolo dell'Osservatorio 2, Padova, Italy
Phillips, David; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Pepe, Francesco; Observatoire Astronomique de l'Université de Gen ve, Versoix, Switzerland
Molinari, Emilio ; INAF-Osservatorio Astronomico di Cagliari, via della Scienza 5, Selargius, Italy
Mignon, Lucile; CNRS, IPAG, France
Micela, Giuseppina ; INAF-Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, Palermo, Italy
Melo, Claudio; European Southern Observatory, Vitacura, Región Metropolitana, Chile
De Medeiros, José R. ; Departamento de Física, Universidade Federal do Rio Grande do Norte, Natal, Brazil
Mayor, Michel; Observatoire Astronomique de l'Université de Gen ve, Versoix, Switzerland
Matson, Rachel A. ; U.S. Naval Observatory, Washington, United States
Martinez Fiorenzano, Aldo F.; Fundación Galileo Galilei-INAF, Rambla José Ana Fernandez Pérez 7, Breña Baja, Spain
Mann, Andrew W. ; Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, United States
Magazzú, Antonio ; Fundación Galileo Galilei-INAF, Rambla José Ana Fernandez Pérez 7, Breña Baja, Spain
Lovis, Christophe; Observatoire Astronomique de l'Université de Gen ve, Versoix, Switzerland
López-Morales, Mercedes ; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Lopez, Eric; NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, United States
Lissauer, Jack J. ; NASA Ames Research Center, Moffett Field, United States
Lépine, Sébastien; Department of Physics and Astronomy, Georgia State University, Atlanta, United States
Law, Nicholas ; Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, United States
Kielkopf, John F. ; Department of Physics and Astronomy, University of Louisville, Louisville, United States
Johnson, John A.; Center for Astrophysics|Harvard and Smithsonian, Cambridge, United States
Jensen, Eric L. N. ; Department of Physics and Astronomy, Swarthmore College, Swarthmore, United States
Howell, Steve B. ; NASA Ames Research Center, Moffett Field, United States
Gonzales, Erica; Department of Astronomy and Astrophysics, University of California, Santa Cruz, United States
Ghedina, Adriano ; Fundación Galileo Galilei-INAF, Rambla José Ana Fernandez Pérez 7, Breña Baja, Spain
Forveille, Thierry ; CNRS, IPAG, France
Figueira, Pedro ; Instituto de Astrofísica e Ciencias do Espa o, Universidade do Porto CAUP, Rua das Estrelas, Porto, Portugal ; European Southern Observatory, Vitacura, Región Metropolitana, Chile
Dumusque, Xavier ; Observatoire Astronomique de l'Université de Gen ve, Versoix, Switzerland
Dressing, Courtney D. ; Astronomy Department, University of California, Berkeley, United States
Doyon, René; Département de physique, Université de Montréal, Montréal, Canada
Díaz, Rodrigo F. ; International Center for Advanced Studies (ICAS) and ICIFI (CONICET), ECyT-UNSAM, Buenos Aires, Argentina
Fabrizio, Luca Di; Fundación Galileo Galilei-INAF, Rambla José Ana Fernandez Pérez 7, Breña Baja, Spain
Delfosse, Xavier; CNRS, IPAG, France
Cosentino, Rosario; Fundación Galileo Galilei-INAF, Rambla José Ana Fernandez Pérez 7, Breña Baja, Spain
Conti, Dennis M. ; American Association of Variable Star Observers, Cambridge, United States
Collins, Kevin I. ; George Mason University, Fairfax, United States
Cameron, Andrew Collier; School of Physics and Astronomy, University of St Andrews North Haugh St Andrews, Fife, United Kingdom
Ciardi, David ; Caltech/IPAC, Pasadena, United States
Caldwell, Douglas A. ; NASA Ames Research Center, Moffett Field, United States
Burke, Christopher ; Department of Earth, Atmospheric and Planetary Sciences and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, United States
Buchhave, Lars ; DTU Space, National Space Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
Briceño, César; Cerro Tololo Inter-American Observatory, Casilla, La Serena, Chile
Boyd, Patricia ; NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, United States
Bouchy, Fran ois; Observatoire Astronomique de l'Université de Gen ve, Versoix, Switzerland
Beichman, Charles; NASA Exoplanet Science Institute, Infrared Processing and Analysis Center, Jet Propulsion Laboratory, Pasadena, United States
Artigau, tienne; Département de physique, Université de Montréal, Montréal, Canada
