Barclay, ThomasMukai, KojiPidhorodetska, Dariaet al.2021-01-252021-01-252019-06-27Barclay, Thomas; Mukai, Koji; Pidhorodetska, Daria; et al.; The L 98-59 System: Three Transiting, Terrestrial-size Planets Orbiting a Nearby M Dwarf; The Astronomical Journal, Volume 158, Number 1 (2019); https://iopscience.iop.org/article/10.3847/1538-3881/ab2459https://doi.org/10.3847/1538-3881/ab2459http://hdl.handle.net/11603/20610Veselin B. Kostov1,2, Joshua E. Schlieder1, Thomas Barclay1,3, Elisa V. Quintana1, Knicole D. Colón1, Jonathan Brande1,4,59, Karen A. Collins5, Adina D. Feinstein6, Samuel Hadden5, Stephen R. Kane7, Laura Kreidberg5, Ethan Kruse1, Christopher Lam1, Elisabeth Matthews8, Benjamin T. Montet6,60, Francisco J. Pozuelos9,10, Keivan G. Stassun11, Jennifer G. Winters5, George Ricker12, Roland Vanderspek12, David Latham5, Sara Seager12,13,14, Joshua Winn15, Jon M. Jenkins16, Dennis Afanasev17, James J. D. Armstrong18, Giada Arney1, Patricia Boyd1, Geert Barentsen19, Khalid Barkaoui10,20, Natalie E. Batalha21, Charles Beichman22, Daniel Bayliss23, Christopher Burke8, Artem Burdanov10, Luca Cacciapuoti24, Andrew Carson1, David Charbonneau5, Jessie Christiansen25, David Ciardi25, Mark Clampin1, Kevin I. Collins26, Dennis M. Conti27, Jeffrey Coughlin2, Giovanni Covone24, Ian Crossfield12, Laetitia Delrez28, Shawn Domagal-Goldman1, Courtney Dressing29, Elsa Ducrot10, Zahra Essack13, Mark E. Everett30, Thomas Fauchez1, Daniel Foreman-Mackey31, Tianjun Gan32, Emily Gilbert6, Michaël Gillon10, Erica Gonzales21, Aaron Hamann6, Christina Hedges19, Hannah Hocutt33, Kelsey Hoffman2, Elliott P. Horch33, Keith Horne34, Steve Howell16, Shane Hynes1, Michael Ireland35, Jonathan M. Irwin5, Giovanni Isopi36, Eric L. N. Jensen37, Emmanuël Jehin9, Lisa Kaltenegger38, John F. Kielkopf39, Ravi Kopparapu1, Nikole Lewis38, Eric Lopez1, Jack J. Lissauer16, Andrew W. Mann40, Franco Mallia36, Avi Mandell1, Rachel A. Matson16, Tsevi Mazeh41, Teresa Monsue1, Sarah E. Moran42, Vickie Moran1, Caroline V. Morley43, Brett Morris44, Philip Muirhead45, Koji Mukai1,3, Susan Mullally46, Fergal Mullally2, Catriona Murray28, Norio Narita47,48,49,50,51, Enric Palle52, Daria Pidhorodetska1, David Quinn1, Howard Relles5, Stephen Rinehart1, Matthew Ritsko1, Joseph E. Rodriguez5, Pamela Rowden53, Jason F. Rowe54, Daniel Sebastian10, Ramotholo Sefako55, Sahar Shahaf41, Avi Shporer12, Naylynn Tañón Reyes1,56, Peter Tenenbaum2,16, Eric B. Ting16, Joseph D. Twicken2,16, Gerard T. van Belle57, Laura Vega1, Jeffrey Volosin1, Lucianne M. Walkowicz58, and Allison Youngblood1We report the Transiting Exoplanet Survey Satellite (TESS) discovery of three terrestrial-size planets transiting L 98-59 (TOI-175, TIC 307210830)—a bright M dwarf at a distance of 10.6 pc. Using the Gaia-measured distance and broadband photometry, we find that the host star is an M3 dwarf. Combined with the TESS transits from three sectors, the corresponding stellar parameters yield planet radii ranging from 0.8 R ⊕ to 1.6 R ⊕. All three planets have short orbital periods, ranging from 2.25 to 7.45 days with the outer pair just wide of a 2:1 period resonance. Diagnostic tests produced by the TESS Data Validation Report and the vetting package DAVE rule out common false-positive sources. These analyses, along with dedicated follow-up and the multiplicity of the system, lend confidence that the observed signals are caused by planets transiting L 98-59 and are not associated with other sources in the field. The L 98-59 system is interesting for a number of reasons: the host star is bright (V = 11.7 mag, K = 7.1 mag) and the planets are prime targets for further follow-up observations including precision radial-velocity mass measurements and future transit spectroscopy with the James Webb Space Telescope; the near-resonant configuration makes the system a laboratory to study planetary system dynamical evolution; and three planets of relatively similar size in the same system present an opportunity to study terrestrial planets where other variables (age, metallicity, etc.) can be held constant. L 98-59 will be observed in four more TESS sectors, which will provide a wealth of information on the three currently known planets and have the potential to reveal additional planets in the system.25 pagesen-USThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.Public Domain Mark 1.0This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.http://creativecommons.org/publicdomain/mark/1.0/Text