1
|
Naponiello L, Mancini L, Sozzetti A, Bonomo AS, Morbidelli A, Dou J, Zeng L, Leinhardt ZM, Biazzo K, Cubillos PE, Pinamonti M, Locci D, Maggio A, Damasso M, Lanza AF, Lissauer JJ, Collins KA, Carter PJ, Jensen ELN, Bignamini A, Boschin W, Bouma LG, Ciardi DR, Cosentino R, Crossfield I, Desidera S, Dumusque X, Fiorenzano AFM, Fukui A, Giacobbe P, Gnilka CL, Ghedina A, Guilluy G, Harutyunyan A, Howell SB, Jenkins JM, Lund MB, Kielkopf JF, Lester KV, Malavolta L, Mann AW, Matson RA, Matthews EC, Nardiello D, Narita N, Pace E, Pagano I, Palle E, Pedani M, Seager S, Schlieder JE, Schwarz RP, Shporer A, Twicken JD, Winn JN, Ziegler C, Zingales T. A super-massive Neptune-sized planet. Nature 2023; 622:255-260. [PMID: 37648866 DOI: 10.1038/s41586-023-06499-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 07/28/2023] [Indexed: 09/01/2023]
Abstract
Neptune-sized planets exhibit a wide range of compositions and densities, depending on factors related to their formation and evolution history, such as the distance from their host stars and atmospheric escape processes. They can vary from relatively low-density planets with thick hydrogen-helium atmospheres1,2 to higher-density planets with a substantial amount of water or a rocky interior with a thinner atmosphere, such as HD 95338 b (ref. 3), TOI-849 b (ref. 4) and TOI-2196 b (ref. 5). The discovery of exoplanets in the hot-Neptune desert6, a region close to the host stars with a deficit of Neptune-sized planets, provides insights into the formation and evolution of planetary systems, including the existence of this region itself. Here we show observations of the transiting planet TOI-1853 b, which has a radius of 3.46 ± 0.08 Earth radii and orbits a dwarf star every 1.24 days. This planet has a mass of 73.2 ± 2.7 Earth masses, almost twice that of any other Neptune-sized planet known so far, and a density of 9.7 ± 0.8 grams per cubic centimetre. These values place TOI-1853 b in the middle of the Neptunian desert and imply that heavy elements dominate its mass. The properties of TOI-1853 b present a puzzle for conventional theories of planetary formation and evolution, and could be the result of several proto-planet collisions or the final state of an initially high-eccentricity planet that migrated closer to its parent star.
Collapse
Affiliation(s)
- Luca Naponiello
- Department of Physics, University of Rome "Tor Vergata", Rome, Italy.
- Department of Physics and Astronomy, University of Florence, Florence, Italy.
- Department of Physics, Sapienza University of Rome, Rome, Italy.
- INAF - Turin Astrophysical Observatory, Pino Torinese, Italy.
| | - Luigi Mancini
- Department of Physics, University of Rome "Tor Vergata", Rome, Italy
- INAF - Turin Astrophysical Observatory, Pino Torinese, Italy
- Max Planck Institute for Astronomy, Heidelberg, Germany
| | | | - Aldo S Bonomo
- INAF - Turin Astrophysical Observatory, Pino Torinese, Italy
| | - Alessandro Morbidelli
- Laboratoire Lagrange, Université Cote d'Azur, CNRS, Observatoire de la Côte d'Azur, Nice, France
| | - Jingyao Dou
- School of Physics, H.H. Wills Physics Laboratory, University of Bristol, Bristol, UK
| | - Li Zeng
- Center for Astrophysics, Harvard & Smithsonian, Cambridge, MA, USA
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA
| | - Zoe M Leinhardt
- School of Physics, H.H. Wills Physics Laboratory, University of Bristol, Bristol, UK
| | - Katia Biazzo
- INAF - Rome Astronomical Observatory, Monte Porzio Catone, Italy
| | - Patricio E Cubillos
- INAF - Turin Astrophysical Observatory, Pino Torinese, Italy
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | | | - Daniele Locci
- INAF - Palermo Astronomical Observatory, Palermo, Italy
| | | | - Mario Damasso
- INAF - Turin Astrophysical Observatory, Pino Torinese, Italy
| | | | - Jack J Lissauer
- NASA Ames Research Center, Moffett Field, CA, USA
- Department of Earth and Planetary Sciences, Stanford University, Stanford, CA, USA
| | - Karen A Collins
- Center for Astrophysics, Harvard & Smithsonian, Cambridge, MA, USA
| | - Philip J Carter
- School of Physics, H.H. Wills Physics Laboratory, University of Bristol, Bristol, UK
| | - Eric L N Jensen
- Department of Physics & Astronomy, Swarthmore College, Swarthmore, PA, USA
| | | | - Walter Boschin
- Fundación Galileo Galilei - INAF, Tenerife, Spain
- Instituto de Astrofísica de Canarias (IAC), Tenerife, Spain
- Departamento de Astrofísica, Universidad de La Laguna (ULL), Tenerife, Spain
| | - Luke G Bouma
- NASA Exoplanet Science Institute - Caltech/IPAC, Pasadena, CA, USA
| | - David R Ciardi
- NASA Exoplanet Science Institute - Caltech/IPAC, Pasadena, CA, USA
| | | | - Ian Crossfield
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS, USA
| | | | - Xavier Dumusque
- Observatoire de Genève, Université de Genève, Versoix, Switzerland
| | | | - Akihiko Fukui
- Instituto de Astrofísica de Canarias (IAC), Tenerife, Spain
- Komaba Institute for Science, The University of Tokyo, Tokyo, Japan
| | - Paolo Giacobbe
- INAF - Turin Astrophysical Observatory, Pino Torinese, Italy
| | - Crystal L Gnilka
- NASA Ames Research Center, Moffett Field, CA, USA
- NASA Exoplanet Science Institute - Caltech/IPAC, Pasadena, CA, USA
| | | | - Gloria Guilluy
- INAF - Turin Astrophysical Observatory, Pino Torinese, Italy
| | | | | | | | - Michael B Lund
- NASA Exoplanet Science Institute - Caltech/IPAC, Pasadena, CA, USA
| | - John F Kielkopf
- Department of Physics and Astronomy, University of Louisville, Louisville, KY, USA
| | | | - Luca Malavolta
- INAF - Padova Astronomical Observatory, Padova, Italy
- Department of Physics and Astronomy, University of Padova, Padova, Italy
| | - Andrew W Mann
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | | | | | - Norio Narita
- Instituto de Astrofísica de Canarias (IAC), Tenerife, Spain
- Komaba Institute for Science, The University of Tokyo, Tokyo, Japan
- Astrobiology Center, Osawa, Mitaka, Japan
| | - Emanuele Pace
- Department of Physics and Astronomy, University of Florence, Florence, Italy
| | | | - Enric Palle
- Instituto de Astrofísica de Canarias (IAC), Tenerife, Spain
- Departamento de Astrofísica, Universidad de La Laguna (ULL), Tenerife, Spain
| | - Marco Pedani
- Fundación Galileo Galilei - INAF, Tenerife, Spain
| | - Sara Seager
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | | | - Avi Shporer
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Joseph D Twicken
- NASA Ames Research Center, Moffett Field, CA, USA
- SETI Institute, Mountain View, CA, USA
| | - Joshua N Winn
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ, USA
| | - Carl Ziegler
- Department of Physics, Engineering & Astronomy, Stephen F. Austin State University, Nacogdoches, TX, USA
| | - Tiziano Zingales
- INAF - Padova Astronomical Observatory, Padova, Italy
- Department of Physics and Astronomy, University of Padova, Padova, Italy
| |
Collapse
|
8
|
Meadows VS, Reinhard CT, Arney GN, Parenteau MN, Schwieterman EW, Domagal-Goldman SD, Lincowski AP, Stapelfeldt KR, Rauer H, DasSarma S, Hegde S, Narita N, Deitrick R, Lustig-Yaeger J, Lyons TW, Siegler N, Grenfell JL. Exoplanet Biosignatures: Understanding Oxygen as a Biosignature in the Context of Its Environment. ASTROBIOLOGY 2018; 18:630-662. [PMID: 29746149 PMCID: PMC6014580 DOI: 10.1089/ast.2017.1727] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 12/15/2017] [Indexed: 05/04/2023]
Abstract
We describe how environmental context can help determine whether oxygen (O2) detected in extrasolar planetary observations is more likely to have a biological source. Here we provide an in-depth, interdisciplinary example of O2 biosignature identification and observation, which serves as the prototype for the development of a general framework for biosignature assessment. Photosynthetically generated O2 is a potentially strong biosignature, and at high abundance, it was originally thought to be an unambiguous indicator for life. However, as a biosignature, O2 faces two major challenges: (1) it was only present at high abundance for a relatively short period of Earth's history and (2) we now know of several potential planetary mechanisms that can generate abundant O2 without life being present. Consequently, our ability to interpret both the presence and absence of O2 in an exoplanetary spectrum relies on understanding the environmental context. Here we examine the coevolution of life with the early Earth's environment to identify how the interplay of sources and sinks may have suppressed O2 release into the atmosphere for several billion years, producing a false negative for biologically generated O2. These studies suggest that planetary characteristics that may enhance false negatives should be considered when selecting targets for biosignature searches. We review the most recent knowledge of false positives for O2, planetary processes that may generate abundant atmospheric O2 without a biosphere. We provide examples of how future photometric, spectroscopic, and time-dependent observations of O2 and other aspects of the planetary environment can be used to rule out false positives and thereby increase our confidence that any observed O2 is indeed a biosignature. These insights will guide and inform the development of future exoplanet characterization missions. Key Words: Biosignatures-Oxygenic photosynthesis-Exoplanets-Planetary atmospheres. Astrobiology 18, 630-662.
Collapse
Affiliation(s)
- Victoria S. Meadows
- Department of Astronomy, University of Washington, Seattle, Washington
- NASA Astrobiology Institute, Virtual Planetary Laboratory Team, Seattle, Washington
| | - Christopher T. Reinhard
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia
- NASA Astrobiology Institute, Alternative Earths Team, Riverside, California
| | - Giada N. Arney
- NASA Astrobiology Institute, Virtual Planetary Laboratory Team, Seattle, Washington
- Planetary Systems Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland
| | - Mary N. Parenteau
- NASA Astrobiology Institute, Virtual Planetary Laboratory Team, Seattle, Washington
- NASA Ames Research Center, Exobiology Branch, Mountain View, California
| | - Edward W. Schwieterman
- NASA Astrobiology Institute, Virtual Planetary Laboratory Team, Seattle, Washington
- NASA Astrobiology Institute, Alternative Earths Team, Riverside, California
- Department of Earth Sciences, University of California, Riverside, California
- NASA Postdoctoral Program, Universities Space Research Association, Columbia, Maryland
- Blue Marble Space Institute of Science, Seattle, Washington
| | - Shawn D. Domagal-Goldman
- NASA Astrobiology Institute, Virtual Planetary Laboratory Team, Seattle, Washington
- Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland
| | - Andrew P. Lincowski
- Department of Astronomy, University of Washington, Seattle, Washington
- NASA Astrobiology Institute, Virtual Planetary Laboratory Team, Seattle, Washington
| | - Karl R. Stapelfeldt
- NASA Exoplanet Exploration Program, Jet Propulsion Laboratory/California Institute of Technology, Pasadena, California
| | - Heike Rauer
- German Aerospace Center, Institute of Planetary Research, Extrasolar Planets and Atmospheres, Berlin, Germany
| | - Shiladitya DasSarma
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Maryland
- Institute of Marine and Environmental Technology, University System of Baltimore, Maryland
| | - Siddharth Hegde
- Carl Sagan Institute, Cornell University, Ithaca, New York
- Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, New York
| | - Norio Narita
- Department of Astronomy, The University of Tokyo, Tokyo, Japan
- Astrobiology Center, NINS, Tokyo, Japan
- National Astronomical Observatory of Japan, NINS, Tokyo, Japan
| | - Russell Deitrick
- Department of Astronomy, University of Washington, Seattle, Washington
- NASA Astrobiology Institute, Virtual Planetary Laboratory Team, Seattle, Washington
| | - Jacob Lustig-Yaeger
- Department of Astronomy, University of Washington, Seattle, Washington
- NASA Astrobiology Institute, Virtual Planetary Laboratory Team, Seattle, Washington
| | - Timothy W. Lyons
- NASA Astrobiology Institute, Alternative Earths Team, Riverside, California
- Department of Earth Sciences, University of California, Riverside, California
| | - Nicholas Siegler
- NASA Exoplanet Exploration Program, Jet Propulsion Laboratory/California Institute of Technology, Pasadena, California
| | - J. Lee Grenfell
- German Aerospace Center, Institute of Planetary Research, Extrasolar Planets and Atmospheres, Berlin, Germany
| |
Collapse
|
10
|
Blumenthal SD, Mandell AM, Hébrard E, Batalha NE, Cubillos PE, Rugheimer S, Wakeford HR. A COMPARISON OF SIMULATED JWST OBSERVATIONS DERIVED FROM EQUILIBRIUM AND NON-EQUILIBRIUM CHEMISTRY MODELS OF GIANT EXOPLANETS. THE ASTROPHYSICAL JOURNAL 2018; 853:10.3847/1538-4357/aa9e51. [PMID: 31806912 PMCID: PMC6893919 DOI: 10.3847/1538-4357/aa9e51] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We aim to see if the difference between equilibrium and disequilibrium chemistry is observable in the atmospheres of transiting planets by the James Webb Space Telescope (JWST). We perform a case study comparing the dayside emission spectra of three planets like HD 189733b, WASP-80b, and GJ436b, in and out of chemical equilibrium at two metallicities each. These three planets were chosen because they span a large range of planetary masses and equilibrium temperatures, from hot and Jupiter-sized to warm and Neptune-sized. We link the one-dimensional disequilibrium chemistry model from Venot et al. (2012) in which thermochemical kinetics, vertical transport, and photochemistry are taken into account, to the one-dimensional, pseudo line-by-line radiative transfer model, Pyrat Bay, developed especially for hot Jupiters, and then simulate JWST spectra using PandExo for comparing the effects of temperature, metallicity, and radius. We find the most significant differences from 4 to 5 μm due to disequilibrium from CO and CO2 abundances, and also H2O for select cases. Our case study shows a certain "sweet spot" of planetary mass, temperature, and metallicity where the difference between equilibrium and disequilibrium is observable. For a planet similar to WASP-80b, JWST's NIRSpec G395M can detect differences due to disequilibrium chemistry with one eclipse event. For a planet similar to GJ 436b, the observability of differences due to disequilibrium chemistry is possible at low metallicity given five eclipse events, but not possible at the higher metallicity.
Collapse
Affiliation(s)
- Sarah D Blumenthal
- NASA Goddard Space Flight Center, Center for Astrobiology, Greenbelt, MD 20771
- University of Maryland Baltimore Country, CRESST
- Astrophysics Group, School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Avi M Mandell
- NASA Goddard Space Flight Center, Center for Astrobiology, Greenbelt, MD 20771
| | - Eric Hébrard
- NASA Goddard Space Flight Center, Center for Astrobiology, Greenbelt, MD 20771
- Astrophysics Group, School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Natasha E Batalha
- NASA Goddard Space Flight Center, Center for Astrobiology, Greenbelt, MD 20771
- Department of Astronomy & Astrophysics, Pennsylvania State University, State College, PA 16801
| | - Patricio E Cubillos
- Space Research Institute, Austrian Academy of Sciences, Schmiedlstraße 6, 8042 Graz, Austria
| | - Sarah Rugheimer
- School of Geography & Geosciences, University of St Andrews, St Andrews, United Kingdom
| | - Hannah R Wakeford
- NASA Goddard Space Flight Center, Center for Astrobiology, Greenbelt, MD 20771
| |
Collapse
|