The Multiplanet System TOI-421*
Artikel i vetenskaplig tidskrift, 2020
We report the discovery of a warm Neptune and a hot sub-Neptune transiting TOI-421 (BD-14 1137, TIC 94986319), a bright (V = 9.9) G9 dwarf star in a visual binary system observed by the Transiting Exoplanet Survey Satellite (TESS) space mission in Sectors 5 and 6. We performed ground-based follow-up observations-comprised of Las Cumbres Observatory Global Telescope transit photometry, NIRC2 adaptive optics imaging, and FIbre-fed Echelle Spectrograph, CORALIE, High Accuracy Radial velocity Planet Searcher, High Resolution echelle Spectrometer, and Planet Finder Spectrograph high-precision Doppler measurements-and confirmed the planetary nature of the 16 day transiting candidate announced by the TESS team. We discovered an additional radial velocity signal with a period of five days induced by the presence of a second planet in the system, which we also found to transit its host star. We found that the inner mini-Neptune, TOI-421 b, has an orbital period of P-b = 5.19672 +/- 0.00049 days, a mass of M-b = 7.17 +/- 0.66 M-circle plus, and a radius of R-b = R-circle plus, whereas the outer warm Neptune, TOI-421 c, has a period of P-c = 16.06819 +/- 0.00035 days, a mass of M-c = 16.42(-1.04)(+1.06)M(circle plus), a radius of R-c = 5.09(-0.15)(+0.16)R(circle plus), and a density of rho(c) = 0.685(-0.072)(+0.080) cm(-3). With its characteristics, the outer planet (rho(c) = 0.685(-0.0072)(+0.080) cm(-3)) is placed in the intriguing class of the super-puffy mini-Neptunes. TOI-421 b and TOI-421 c are found to be well-suited for atmospheric characterization. Our atmospheric simulations predict significant Ly alpha transit absorption, due to strong hydrogen escape in both planets, as well as the presence of detectable CH4 in the atmosphere of TOI-421 c if equilibrium chemistry is assumed.
Författare
Ilaria Carleo
Istituto nazionale di astrofisica (INAF)
Wesleyan University
Davide Gandolfi
Universita degli Studi di Torino
Oscar Barragan
University of Oxford
John H. Livingston
University of Tokyo
Carina Persson
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Kristine W. F. Lam
Technische Universität Berlin
Aline Vidotto
Trinity College Dublin
Michael B. Lund
California Institute of Technology (Caltech)
Carolina Villarreal D'Angelo
Trinity College Dublin
Karen A. Collins
Harvard-Smithsonian Center for Astrophysics
Luca Fossati
Österreichische Akademie der Wissenschaften
Andrew W. Howard
California Institute of Technology (Caltech)
Daria Kubyshkina
Österreichische Akademie der Wissenschaften
Rafael Brahm
Instituto Milenio de Astrofísica
Universidad Adolfo Ibanez
Antonija Oklopcic
Harvard-Smithsonian Center for Astrophysics
Paul Molliere
Max-Planck-Gesellschaft
Seth Redfield
Wesleyan University
Luisa Maria Serrano
Universidade do Porto
Universita degli Studi di Torino
Fei Dai
Massachusetts Institute of Technology (MIT)
Princeton University
Malcolm Fridlund
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Francesco Borsa
Istituto nazionale di astrofisica (INAF)
Judith Korth
Universität zu Köln
Massimiliano Esposito
Thüringer Landessternwarte Tautenburg
Matias R. Diaz
Universidad de Chile (UCH)
Louise Dyregaard Nielsen
Université de Genève
Coel Hellier
Keele University
Savita Mathur
Instituto de Astrofísica de Canarias
Universidad de la Laguna
Hans J. Deeg
Universidad de la Laguna
Instituto de Astrofísica de Canarias
Artie P. Hatzes
Thüringer Landessternwarte Tautenburg
Serena Benatti
Istituto nazionale di astrofisica (INAF)
Florian Rodler
European Southern Observatory (ESO)
Javier Alarcon
European Southern Observatory (ESO)
Lorenzo Spina
ARC Centre of Excellence for All-sky Astrophysics (CAASTRO)
Monash University
Angela R. G. Santos
Space Science Institute
Iskra Georgieva
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Rafael A. Garcia
Université Paris Diderot
Université Paris-Saclay
Lucia Gonzalez-Cuesta
Instituto de Astrofísica de Canarias
George R. Ricker
Massachusetts Institute of Technology (MIT)
Roland Vanderspek
Massachusetts Institute of Technology (MIT)
David W. Latham
Harvard-Smithsonian Center for Astrophysics
Sara Seager
Massachusetts Institute of Technology (MIT)
Joshua N. Winn
Princeton University
Jon M. Jenkins
National Aeronautics and Space Administration (NASA)
Simon Albrecht
Aarhus Universitet
Natalie M. Batalha
University of California at Santa Cruz
Corey Beard
University of California at Irvine (UCI)
Patricia T. Boyd
National Aeronautics and Space Administration (NASA)
Francois Bouchy
Université de Genève
Jennifer A. Burt
California Institute of Technology (Caltech)
R. Paul Butler
Carnegie Institution for Science
Juan Cabrera
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Ashley Chontos
University of Hawaii
David R. Ciardi
California Institute of Technology (Caltech)
William D. Cochran
The University of Texas at Austin
Collins
George Mason University
Jeffrey D. Crane
Carnegie Institution for Science
Ian Crossfield
University of Kansas
Szilard Csizmadia
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Diana Dragomir
University of New Mexico
Courtney Dressing
University of California at Berkeley
Philipp Eigmueller
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Michael Endl
The University of Texas at Austin
Anders Erikson
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Nestor Espinoza
Space Telescope Science Institute (STScI)
Michael Fausnaugh
Massachusetts Institute of Technology (MIT)
Fabo Feng
Carnegie Institution for Science
Erin Flowers
Princeton University
Benjamin Fulton
California Institute of Technology (Caltech)
Erica J. Gonzales
University of California at Santa Cruz
Nolan Grieves
Université de Genève
Sascha Grziwa
Universität zu Köln
Eike W. Guenther
Thüringer Landessternwarte Tautenburg
Natalia M. Guerrero
Massachusetts Institute of Technology (MIT)
Thomas Henning
Max-Planck-Gesellschaft
Diego Hidalgo
Instituto de Astrofísica de Canarias
Teruyuki Hirano
Tokyo Institute of Technology
Maria Hjorth
Aarhus Universitet
Daniel Huber
University of Hawaii
Howard Isaacson
University of Southern Queensland
University of California at Berkeley
Matias Jones
European Southern Observatory (ESO)
Andres Jordan
Universidad Adolfo Ibanez
Instituto Milenio de Astrofísica
Petr Kabath
Czech Academy of Sciences
Stephen R. Kane
University of California at Riverside
Emil Knudstrup
Aarhus Universitet
Jack Lubin
University of California at Irvine (UCI)
Rafael Luque
Instituto de Astrofísica de Canarias
Universidad de la Laguna
Ismael Mireles
Massachusetts Institute of Technology (MIT)
Norio Narita
Instituto de Astrofísica de Canarias
National Institutes of Natural Sciences
Japan Science and Technology Agency
University of Tokyo
David Nespral
Instituto de Astrofísica de Canarias
Universidad de la Laguna
Prajwal Niraula
Massachusetts Institute of Technology (MIT)
Grzegorz Nowak
Universidad de la Laguna
Instituto de Astrofísica de Canarias
Enric Palle
Instituto de Astrofísica de Canarias
Universidad de la Laguna
Martin Paetzold
Universität zu Köln
Erik A. Petigura
University of California at Los Angeles
Jorge Prieto-Arranz
Universidad de la Laguna
Instituto de Astrofísica de Canarias
Heike Rauer
Freie Universität Berlin
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Technische Universität Berlin
Paul Robertson
University of California at Irvine (UCI)
Mark E. Rose
National Aeronautics and Space Administration (NASA)
Arpita Roy
California Institute of Technology (Caltech)
Paula Sarkis
Max-Planck-Gesellschaft
Joshua E. Schlieder
National Aeronautics and Space Administration (NASA)
Damien Segransan
Université de Genève
Stephen Shectman
Carnegie Institution for Science
Marek Skarka
Czech Academy of Sciences
Masarykova Univerzita
Alexis M. S. Smith
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Jeffrey C. Smith
National Aeronautics and Space Administration (NASA)
Keivan Stassun
Vanderbilt University
Johanna Teske
Carnegie Institution for Science
Joseph D. Twicken
National Aeronautics and Space Administration (NASA)
Vincent Van Eylen
University College London (UCL)
Sharon Wang
Carnegie Institution for Science
Lauren M. Weiss
University of Hawaii
Aurelien Wyttenbach
Max-Planck-Gesellschaft
Université Grenoble Alpes
Université de Genève
Universiteit Leiden
Astronomical Journal
0004-6256 (ISSN) 1538-3881 (eISSN)
Vol. 160 3 114Ämneskategorier (SSIF 2011)
Meteorologi och atmosfärforskning
Astronomi, astrofysik och kosmologi
Atom- och molekylfysik och optik
DOI
10.3847/1538-3881/aba124