1. A remnant planetary core in the hot-Neptune desert
- Author
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David J. Armstrong, Théo A. Lopez, Vardan Adibekyan, Richard A. Booth, Edward M. Bryant, Karen A. Collins, Magali Deleuil, Alexandre Emsenhuber, Chelsea X. Huang, George W. King, Jorge Lillo-Box, Jack J. Lissauer, Elisabeth Matthews, Olivier Mousis, Louise D. Nielsen, Hugh Osborn, Jon Otegi, Nuno C. Santos, Sérgio G. Sousa, Keivan G. Stassun, Dimitri Veras, Carl Ziegler, Jack S. Acton, Jose M. Almenara, David R. Anderson, David Barrado, Susana C. C. Barros, Daniel Bayliss, Claudia Belardi, Francois Bouchy, César Briceño, Matteo Brogi, David J. A. Brown, Matthew R. Burleigh, Sarah L. Casewell, Alexander Chaushev, David R. Ciardi, Kevin I. Collins, Knicole D. Colón, Benjamin F. Cooke, Ian J. M. Crossfield, Rodrigo F. Díaz, Elisa Delgado Mena, Olivier D. S. Demangeon, Caroline Dorn, Xavier Dumusque, Philipp Eigmüller, Michael Fausnaugh, Pedro Figueira, Tianjun Gan, Siddharth Gandhi, Samuel Gill, Erica J. Gonzales, Michael R. Goad, Maximilian N. Günther, Ravit Helled, Saeed Hojjatpanah, Steve B. Howell, James Jackman, James S. Jenkins, Jon M. Jenkins, Eric L. N. Jensen, Grant M. Kennedy, David W. Latham, Nicholas Law, Monika Lendl, Michael Lozovsky, Andrew W. Mann, Maximiliano Moyano, James McCormac, Farzana Meru, Christoph Mordasini, Ares Osborn, Don Pollacco, Didier Queloz, Liam Raynard, George R. Ricker, Pamela Rowden, Alexandre Santerne, Joshua E. Schlieder, Sara Seager, Lizhou Sha, Thiam-Guan Tan, Rosanna H. Tilbrook, Eric Ting, Stéphane Udry, Roland Vanderspek, Christopher A. Watson, Richard G. West, Paul A. Wilson, Joshua N. Winn, Peter Wheatley, Jesus Noel Villasenor, Jose I. Vines, Zhuchang Zhan, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Armstrong, David J [0000-0002-5080-4117], Collins, Karen A [0000-0001-6588-9574], Emsenhuber, Alexandre [0000-0002-8811-1914], Lillo-Box, Jorge [0000-0003-3742-1987], Lissauer, Jack J [0000-0001-6513-1659], Santos, Nuno C [0000-0003-4422-2919], Stassun, Keivan G [0000-0002-3481-9052], Veras, Dimitri [0000-0001-8014-6162], Barrado, David [0000-0002-5971-9242], Collins, Kevin I [0000-0003-2781-3207], Demangeon, Olivier DS [0000-0001-7918-0355], Dumusque, Xavier [0000-0002-9332-2011], Eigmüller, Philipp [0000-0003-4096-0594], Jenkins, Jon M [0000-0002-4715-9460], Jensen, Eric LN [0000-0002-4625-7333], Kennedy, Grant M [0000-0001-6831-7547], Mordasini, Christoph [0000-0002-1013-2811], Santerne, Alexandre [0000-0002-3586-1316], Seager, Sara [0000-0002-6892-6948], Sha, Lizhou [0000-0001-5401-8079], Udry, Stéphane [0000-0001-7576-6236], West, Richard G [0000-0001-6604-5533], Wilson, Paul A [0000-0002-7823-1090], Winn, Joshua N [0000-0002-4265-047X], Wheatley, Peter [0000-0003-1452-2240], Apollo - University of Cambridge Repository, Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, Collins, K. A. [0000-0002-4317-142X], Lillo Box, J. [0000-0003-3742-1987], Matthews, E. [0000-0003-0593-1560], Sousa, S. [0000-0002-3631-6440], National Aeronautics and Space Administration (NASA), Fundação para a Ciência e a Tecnologia (FCT), Agencia Estatal de Investigación (AEI), Science and Technology Facilities Council (STFC), Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT), Unidad de Excelencia María de Maeztu del Instituto Nacional de Técnica Aeroespacial y CSIC, and French Programme National de Planetologie
- Subjects
Extrasolare Planeten und Atmosphären ,astro-ph.SR ,010504 meteorology & atmospheric sciences ,Gas giant ,530 Physics ,FOS: Physical sciences ,TOI-849b ,01 natural sciences ,Astrobiology ,Planet ,0103 physical sciences ,Planetary Core ,Astrophysics::Solar and Stellar Astrophysics ,Hot Neptune ,Desert ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,QB ,Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,Multidisciplinary ,Planetary core ,520 Astronomy ,Giant planet ,620 Engineering ,Accretion (astrophysics) ,Exoplanet ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,[SDU]Sciences of the Universe [physics] ,astro-ph.EP ,Neptune ,Astrophysics::Earth and Planetary Astrophysics ,Planetary mass ,Astrophysics - Earth and Planetary Astrophysics - Abstract
The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. Planets found in and near the typically barren hot-Neptune 'desert' (a region in mass-radius space that contains few planets) have proved to be particularly valuable in this regard. These planets include HD149026b, which is thought to have an unusually massive core, and recent discoveries such as LTT9779b and NGTS-4b, on which photoevaporation has removed a substantial part of their outer atmospheres. Here we report observations of the planet TOI-849b, which has a radius smaller than Neptune's but an anomalously large mass of $39.1^{+2.7}_{-2.6}$ Earth masses and a density of $5.2^{+0.7}_{-0.8}$ grams per cubic centimetre, similar to Earth's. Interior structure models suggest that any gaseous envelope of pure hydrogen and helium consists of no more than $3.9^{+0.8}_{-0.9}$ per cent of the total planetary mass. The planet could have been a gas giant before undergoing extreme mass loss via thermal self-disruption or giant planet collisions, or it could have avoided substantial gas accretion, perhaps through gap opening or late formation. Although photoevaporation rates cannot account for the mass loss required to reduce a Jupiter-like gas giant, they can remove a small (a few Earth masses) hydrogen and helium envelope on timescales of several billion years, implying that any remaining atmosphere on TOI-849b is likely to be enriched by water or other volatiles from the planetary interior. We conclude that TOI-849b is the remnant core of a giant planet., Published in Nature. This is a preprint of the article, before minor changes made during the refereeing and editing process. The published PDF is at https://www.nature.com/articles/s41586-020-2421-7 and can be accessed for free by following this link: https://rdcu.be/b5miB . Abstract updated to match published version
- Published
- 2020
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