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Binns J, Hermann A, Peña-Alvarez M, Donnelly ME, Wang M, Kawaguchi SI, Gregoryanz E, Howie RT, Dalladay-Simpson P. Superionicity, disorder, and bandgap closure in dense hydrogen chloride. SCIENCE ADVANCES 2021; 7:eabi9507. [PMID: 34516915 PMCID: PMC8442878 DOI: 10.1126/sciadv.abi9507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
Hydrogen bond networks play a crucial role in biomolecules and molecular materials such as ices. How these networks react to pressure directs their properties at extreme conditions. We have studied one of the simplest hydrogen bond formers, hydrogen chloride, from crystallization to metallization, covering a pressure range of more than 2.5 million atmospheres. Following hydrogen bond symmetrization, we identify a previously unknown phase by the appearance of new Raman modes and changes to x-ray diffraction patterns that contradict previous predictions. On further compression, a broad Raman band supersedes the well-defined excitations of phase V, despite retaining a crystalline chlorine substructure. We propose that this mode has its origin in proton (H+) mobility and disorder. Above 100 GPa, the optical bandgap closes linearly with extrapolated metallization at 240(10) GPa. Our findings suggest that proton dynamics can drive changes in these networks even at very high densities.
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Affiliation(s)
- Jack Binns
- Center for High Pressure Science & Technology Advanced Research, 1690 Cailun Rd, Pudong, Shanghai 201203, China
| | - Andreas Hermann
- School of Physics and Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3JZ, UK
| | - Miriam Peña-Alvarez
- School of Physics and Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3JZ, UK
| | - Mary-Ellen Donnelly
- Center for High Pressure Science & Technology Advanced Research, 1690 Cailun Rd, Pudong, Shanghai 201203, China
| | - Mengnan Wang
- Center for High Pressure Science & Technology Advanced Research, 1690 Cailun Rd, Pudong, Shanghai 201203, China
| | | | - Eugene Gregoryanz
- Center for High Pressure Science & Technology Advanced Research, 1690 Cailun Rd, Pudong, Shanghai 201203, China
- School of Physics and Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3JZ, UK
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, China
| | - Ross T. Howie
- Center for High Pressure Science & Technology Advanced Research, 1690 Cailun Rd, Pudong, Shanghai 201203, China
| | - Philip Dalladay-Simpson
- Center for High Pressure Science & Technology Advanced Research, 1690 Cailun Rd, Pudong, Shanghai 201203, China
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Edwards B, Rice M, Zingales T, Tessenyi M, Waldmann I, Tinetti G, Pascale E, Savini G, Sarkar S. Exoplanet spectroscopy and photometry with the Twinkle space telescope. EXPERIMENTAL ASTRONOMY 2018; 47:29-63. [PMID: 32684665 PMCID: PMC7357794 DOI: 10.1007/s10686-018-9611-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 11/14/2018] [Indexed: 06/11/2023]
Abstract
The Twinkle space telescope has been designed for the characterisation of exoplanets and Solar System objects. Operating in a low Earth, Sun-synchronous orbit, Twinkle is equipped with a 45 cm telescope and visible (0.4 - 1 μm) and infrared (1.3 - 4.5 μm) spectrometers which can be operated simultaneously. Twinkle is a general observatory which will provide on-demand observations of a wide variety of targets within wavelength ranges that are currently not accessible using other space telescopes or accessible only to oversubscribed observatories in the short-term future. Here we explore the ability of Twinkle's spectrometers to characterise the currently-known exoplanets. We study the spectral resolution achievable by combining multiple observations for various planetary and stellar types. We also simulate spectral retrievals for some well-known planets (HD 209458 b, GJ 3470 b and 55 Cnc e). From the exoplanets known today, we find that with a single transit or eclipse, Twinkle could probe 89 planets at low spectral resolution (R < 20) as well as 12 planets at higher resolution (R > 20) in channel 1 (1.3 - 4.5 μm). With 10 observations, the atmospheres of 144 planets could be characterised with R <20 and 81 at higher resolutions. Upcoming surveys will reveal thousands of new exoplanets, many of which will be located within Twinkle's field of regard. TESS in particular is predicted to discover many targets around bright stars which will be suitable for follow-up observations. We include these anticipated planets and find that the number of planets Twinkle could observe in the near infrared in a single transit or eclipse increases R > 20. By stacking 10 transits, there are 1185 potential targets for study at R < 20 as well as 388 planets at higher resolutions. The majority of targets are found to be large gaseous planets although by stacking multiple observations smaller planets around bright stars (e.g. 55 Cnc e) could be observed with Twinkle. Photometry and low resolution spectroscopy with Twinkle will be useful to refine planetary, stellar and orbital parameters, monitor stellar activity through time and search for transit time and duration variations (TTVs and TDVs). Refinement of these parameters could be used to in the planning of observations with larger space-based observatories such as JWST and ARIEL. For planets orbiting very bright stars, Twinkle observations at higher spectral resolution will enable us to probe the chemical and thermal properties of an atmosphere. Simultaneous coverage across a wide wavelength range will reduce the degeneracies seen with Hubble and provide access to detections of a wide range molecules. There is the potential to revisit them many times over the mission lifetime to detect variations in cloud cover.
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Affiliation(s)
- Billy Edwards
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT UK
| | - Malena Rice
- Department of Astronomy, Yale University, Steinbach Hall, New Haven, CT 06511 USA
| | | | - Marcell Tessenyi
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT UK
- Blue Skies Space Ltd., 69 Wilson Street, London, EC2A 2BB UK
| | - Ingo Waldmann
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT UK
| | - Giovanna Tinetti
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT UK
- Blue Skies Space Ltd., 69 Wilson Street, London, EC2A 2BB UK
| | - Enzo Pascale
- Dipartimento di Fisica, La Sapienza Universita di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy
- School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff, CF24 3AA UK
| | - Giorgio Savini
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT UK
- Blue Skies Space Ltd., 69 Wilson Street, London, EC2A 2BB UK
| | - Subhajit Sarkar
- School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff, CF24 3AA UK
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Fujii Y, Angerhausen D, Deitrick R, Domagal-Goldman S, Grenfell JL, Hori Y, Kane SR, Pallé E, Rauer H, Siegler N, Stapelfeldt K, Stevenson KB. Exoplanet Biosignatures: Observational Prospects. ASTROBIOLOGY 2018; 18:739-778. [PMID: 29938537 PMCID: PMC6016572 DOI: 10.1089/ast.2017.1733] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 03/13/2018] [Indexed: 05/04/2023]
Abstract
Exoplanet hunting efforts have revealed the prevalence of exotic worlds with diverse properties, including Earth-sized bodies, which has fueled our endeavor to search for life beyond the Solar System. Accumulating experiences in astrophysical, chemical, and climatological characterization of uninhabitable planets are paving the way to characterization of potentially habitable planets. In this paper, we review our possibilities and limitations in characterizing temperate terrestrial planets with future observational capabilities through the 2030s and beyond, as a basis of a broad range of discussions on how to advance "astrobiology" with exoplanets. We discuss the observability of not only the proposed biosignature candidates themselves but also of more general planetary properties that provide circumstantial evidence, since the evaluation of any biosignature candidate relies on its context. Characterization of temperate Earth-sized planets in the coming years will focus on those around nearby late-type stars. The James Webb Space Telescope (JWST) and later 30-meter-class ground-based telescopes will empower their chemical investigations. Spectroscopic studies of potentially habitable planets around solar-type stars will likely require a designated spacecraft mission for direct imaging, leveraging technologies that are already being developed and tested as part of the Wide Field InfraRed Survey Telescope (WFIRST) mission. Successful initial characterization of a few nearby targets will be an important touchstone toward a more detailed scrutiny and a larger survey that are envisioned beyond 2030. The broad outlook this paper presents may help develop new observational techniques to detect relevant features as well as frameworks to diagnose planets based on the observables. Key Words: Exoplanets-Biosignatures-Characterization-Planetary atmospheres-Planetary surfaces. Astrobiology 18, 739-778.
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Affiliation(s)
- Yuka Fujii
- NASA Goddard Institute for Space Studies, New York, New York, USA
- Earth-Life Science Institute, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo, Japan
| | - Daniel Angerhausen
- CSH Fellow for Exoplanetary Astronomy, Center for Space and Habitability (CSH), Universität Bern, Bern, Switzerland
- Blue Marble Space Institute of Science, Seattle, Washington, USA
| | - Russell Deitrick
- Department of Astronomy, University of Washington, Seattle, Washington, USA
- NASA Astrobiology Institute's Virtual Planetary Laboratory
| | - Shawn Domagal-Goldman
- NASA Astrobiology Institute's Virtual Planetary Laboratory
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - John Lee Grenfell
- Department of Extrasolar Planets and Atmospheres (EPA), Institute of Planetary Research, German Aerospace Centre (DLR), Berlin, Germany
| | - Yasunori Hori
- Astrobiology Center, National Institutes of Natural Sciences (NINS), Mitaka, Tokyo, Japan
| | - Stephen R. Kane
- Department of Earth Sciences, University of California, Riverside, California, USA
| | - Enric Pallé
- Instituto de Astrofísica de Canarias, La Laguna, Tenerife, Spain
- Departamento de Astrofísica, Universidad de La Laguna, Tenerife, Spain
| | - Heike Rauer
- Department of Extrasolar Planets and Atmospheres (EPA), Institute of Planetary Research, German Aerospace Centre (DLR), Berlin, Germany
- Center for Astronomy and Astrophysics, Berlin Institute of Technology, Berlin, Germany
| | - Nicholas Siegler
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- NASA Exoplanet Exploration Office
| | - Karl Stapelfeldt
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- NASA Exoplanet Exploration Office
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Thompson SE, Coughlin JL, Hoffman K, Mullally F, Christiansen JL, Burke CJ, Bryson S, Batalha N, Haas MR, Catanzarite J, Rowe JF, Barentsen G, Caldwell DA, Clarke BD, Jenkins JM, Li J, Latham DW, Lissauer JJ, Mathur S, Morris RL, Seader SE, Smith JC, Klaus TC, Twicken JD, Van Cleve JE, Wohler B, Akeson R, Ciardi DR, Cochran WD, Henze CE, Howell SB, Huber D, Prša A, Ramírez SV, Morton TD, Barclay T, Campbell JR, Chaplin WJ, Charbonneau D, Christensen-Dalsgaard J, Dotson JL, Doyle L, Dunham EW, Dupree AK, Ford EB, Geary JC, Girouard FR, Isaacson H, Kjeldsen H, Quintana EV, Ragozzine D, Shporer A, Aguirre VS, Steffen JH, Still M, Tenenbaum P, Welsh WF, Wolfgang A, Zamudio KA, Koch DG, Borucki WJ. PLANETARY CANDIDATES OBSERVED BY Kepler. VIII. A FULLY AUTOMATED CATALOG WITH MEASURED COMPLETENESS AND RELIABILITY BASED ON DATA RELEASE 25. THE ASTROPHYSICAL JOURNAL. SUPPLEMENT SERIES 2018; 235:38. [PMID: 32908325 PMCID: PMC7477822 DOI: 10.3847/1538-4365/aab4f9] [Citation(s) in RCA: 255] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We present the Kepler Object of Interest (KOI) catalog of transiting exoplanets based on searching four years of Kepler time series photometry (Data Release 25, Q1-Q17). The catalog contains 8054 KOIs of which 4034 are planet candidates with periods between 0.25 and 632 days. Of these candidates, 219 are new in this catalog and include two new candidates in multi-planet systems (KOI-82.06 and KOI-2926.05), and ten new high-reliability, terrestrial-size, habitable zone candidates. This catalog was created using a tool called the Robovetter which automatically vets the DR25 Threshold Crossing Events (TCEs) found by the Kepler Pipeline (Twicken et al. 2016). Because of this automation, we were also able to vet simulated data sets and therefore measure how well the Robovetter separates those TCEs caused by noise from those caused by low signal-to-noise transits. Because of these measurements we fully expect that this catalog can be used to accurately calculate the frequency of planets out to Kepler's detection limit, which includes temperate, super-Earth size planets around GK dwarf stars in our Galaxy. This paper discusses the Robovetter and the metrics it uses to decide which TCEs are called planet candidates in the DR25 KOI catalog. We also discuss the simulated transits, simulated systematic noise, and simulated astrophysical false positives created in order to characterize the properties of the final catalog. For orbital periods less than 100 d the Robovetter completeness (the fraction of simulated transits that are determined to be planet candidates) across all observed stars is greater than 85%. For the same period range, the catalog reliability (the fraction of candidates that are not due to instrumental or stellar noise) is greater than 98%. However, for low signal-to-noise candidates found between 200 and 500 days, our measurements indicate that the Robovetter is 73.5% complete and 37.2% reliable across all searched stars (or 76.7% complete and 50.5% reliable when considering just the FGK dwarf stars). We describe how the measured completeness and reliability varies with period, signal-to-noise, number of transits, and stellar type. Also, we discuss a value called the disposition score which provides an easy way to select a more reliable, albeit less complete, sample of candidates. The entire KOI catalog, the transit fits using Markov chain Monte Carlo methods, and all of the simulated data used to characterize this catalog are available at the NASA Exoplanet Archive.
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Affiliation(s)
- Susan E. Thompson
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- NASA Ames Research Center, Moffett Field, CA 94035, USA
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218
| | - Jeffrey L. Coughlin
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Kelsey Hoffman
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
| | - Fergal Mullally
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- NASA Ames Research Center, Moffett Field, CA 94035, USA
- Orbital Insight, 100 W Evelyn Ave #110, Mountain View, CA 94041
| | | | - Christopher J. Burke
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- NASA Ames Research Center, Moffett Field, CA 94035, USA
- MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, 37-241, Cambridge, MA 02139
| | - Steve Bryson
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | | | | | - Joseph Catanzarite
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Jason F. Rowe
- Dept. of Physics and Astronomy, Bishop’s University, 2600 College St., Sherbrooke, QC, J1M 1Z7, Canada
| | - Geert Barentsen
- Bay Area Environmental Research Institute, 625 2nd St., Ste 209, Petaluma, CA 94952, USA
| | - Douglas A. Caldwell
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Bruce D. Clarke
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | | | - Jie Li
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
| | - David W. Latham
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge MA 02138, USA
| | | | - Savita Mathur
- Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA
| | - Robert L. Morris
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Shawn E. Seader
- Rincon Research Corporation,101 N Wilmot Rd, Tucson, AZ 85711
| | - Jeffrey C. Smith
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Todd C. Klaus
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Joseph D. Twicken
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | | | - Bill Wohler
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Rachel Akeson
- IPAC-NExScI, Mail Code 100-22, Caltech, 1200 E. California Blvd. Pasadena, CA 91125
| | - David R. Ciardi
- IPAC-NExScI, Mail Code 100-22, Caltech, 1200 E. California Blvd. Pasadena, CA 91125
| | - William D. Cochran
- McDonald Observatory and Department of Astronomy, University of Texas at Austin, Austin, TX 78712
| | | | | | - Daniel Huber
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- Institute for Astronomy, University of Hawai‘i, 2680 Woodlawn Drive, Honolulu, HI 96822, USA
- Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006, Australia
- Stellar Astrophysics Centre, Dept. of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Andrej Prša
- Villanova University, Dept. of Astrophysics and Planetary Science, 800 Lancaster Ave, Villanova PA 19085
| | - Solange V. Ramírez
- IPAC-NExScI, Mail Code 100-22, Caltech, 1200 E. California Blvd. Pasadena, CA 91125
| | - Timothy D. Morton
- Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08544, USA
| | - Thomas Barclay
- NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771
| | - Jennifer R. Campbell
- NASA Ames Research Center, Moffett Field, CA 94035, USA
- KRBwyle, 2400 Nasa Parkway, Houston, TX 77058 USA
| | - William J. Chaplin
- Stellar Astrophysics Centre, Dept. of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
- School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - David Charbonneau
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge MA 02138, USA
| | - Jørgen Christensen-Dalsgaard
- Stellar Astrophysics Centre, Dept. of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | | | - Laurance Doyle
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- Institute for the Metaphysics of Physics, Principia College, One Maybeck Place, Elsah, Illinois 62028
| | | | - Andrea K. Dupree
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge MA 02138, USA
| | - Eric B. Ford
- Dept. of Astronomy & Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA, 16802, USA
- Center for Exoplanets and Habitable Worlds, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA, 16802, USA
- Center for Astrostatistics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA, 16802, USA
- Institute for CyberScience, The Pennsylvania State University
| | - John C. Geary
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge MA 02138, USA
| | - Forrest R. Girouard
- NASA Ames Research Center, Moffett Field, CA 94035, USA
- Orbital Sciences Corporation, 2401 East El Segundo Boulevard, Suite 200, El Segundo, CA 90245, USA
| | | | - Hans Kjeldsen
- Stellar Astrophysics Centre, Dept. of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Elisa V. Quintana
- NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771
| | - Darin Ragozzine
- Brigham Young University, Department of Physics and Astronomy, N283 ESC, Provo, UT 84602, USA
| | - Avi Shporer
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Victor Silva Aguirre
- Stellar Astrophysics Centre, Dept. of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Jason H. Steffen
- University of Nevada, Las Vegas, 4505 S Maryland Pkwy, Las Vegas, NV 89154
| | - Martin Still
- Bay Area Environmental Research Institute, 625 2nd St., Ste 209, Petaluma, CA 94952, USA
| | - Peter Tenenbaum
- SETI Institute, 189 Bernardo Ave, Suite 200, Mountain View, CA 94043, USA
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - William F. Welsh
- Department of Astronomy, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1221
| | - Angie Wolfgang
- Dept. of Astronomy & Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA, 16802, USA
- Center for Exoplanets and Habitable Worlds, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Khadeejah A Zamudio
- NASA Ames Research Center, Moffett Field, CA 94035, USA
- KRBwyle, 2400 Nasa Parkway, Houston, TX 77058 USA
| | - David G. Koch
- NASA Ames Research Center, Moffett Field, CA 94035, USA
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Identifying Exoplanets with Deep Learning: A Five-planet Resonant Chain around Kepler-80 and an Eighth Planet around Kepler-90. ACTA ACUST UNITED AC 2018. [DOI: 10.3847/1538-3881/aa9e09] [Citation(s) in RCA: 180] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Abstract
The nearly circular (mean eccentricity [Formula: see text]) and coplanar (mean mutual inclination [Formula: see text]) orbits of the solar system planets motivated Kant and Laplace to hypothesize that planets are formed in disks, which has developed into the widely accepted theory of planet formation. The first several hundred extrasolar planets (mostly Jovian) discovered using the radial velocity (RV) technique are commonly on eccentric orbits ([Formula: see text]). This raises a fundamental question: Are the solar system and its formation special? The Kepler mission has found thousands of transiting planets dominated by sub-Neptunes, but most of their orbital eccentricities remain unknown. By using the precise spectroscopic host star parameters from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) observations, we measure the eccentricity distributions for a large (698) and homogeneous Kepler planet sample with transit duration statistics. Nearly half of the planets are in systems with single transiting planets (singles), whereas the other half are multiple transiting planets (multiples). We find an eccentricity dichotomy: on average, Kepler singles are on eccentric orbits with [Formula: see text] 0.3, whereas the multiples are on nearly circular [Formula: see text] and coplanar [Formula: see text] degree) orbits similar to those of the solar system planets. Our results are consistent with previous studies of smaller samples and individual systems. We also show that Kepler multiples and solar system objects follow a common relation [[Formula: see text](1-2)[Formula: see text]] between mean eccentricities and mutual inclinations. The prevalence of circular orbits and the common relation may imply that the solar system is not so atypical in the galaxy after all.
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Mills SM, Fabrycky DC, Migaszewski C, Ford EB, Petigura E, Isaacson H. A resonant chain of four transiting, sub-Neptune planets. Nature 2016; 533:509-12. [DOI: 10.1038/nature17445] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 02/11/2016] [Indexed: 11/09/2022]
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10
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Borucki WJ. KEPLER Mission: development and overview. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:036901. [PMID: 26863223 DOI: 10.1088/0034-4885/79/3/036901] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The Kepler Mission is a space observatory launched in 2009 by NASA to monitor 170,000 stars over a period of four years to determine the frequency of Earth-size and larger planets in and near the habitable zone of Sun-like stars, the size and orbital distributions of these planets, and the types of stars they orbit. Kepler is the tenth in the series of NASA Discovery Program missions that are competitively-selected, PI-directed, medium-cost missions. The Mission concept and various instrument prototypes were developed at the Ames Research Center over a period of 18 years starting in 1983. The development of techniques to do the 10 ppm photometry required for Mission success took years of experimentation, several workshops, and the exploration of many 'blind alleys' before the construction of the flight instrument. Beginning in 1992 at the start of the NASA Discovery Program, the Kepler Mission concept was proposed five times before its acceptance for mission development in 2001. During that period, the concept evolved from a photometer in an L2 orbit that monitored 6000 stars in a 50 sq deg field-of-view (FOV) to one that was in a heliocentric orbit that simultaneously monitored 170,000 stars with a 105 sq deg FOV. Analysis of the data to date has detected over 4600 planetary candidates which include several hundred Earth-size planetary candidates, over a thousand confirmed planets, and Earth-size planets in the habitable zone (HZ). These discoveries provide the information required for estimates of the frequency of planets in our galaxy. The Mission results show that most stars have planets, many of these planets are similar in size to the Earth, and that systems with several planets are common. Although planets in the HZ are common, many are substantially larger than Earth.
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Affiliation(s)
- William J Borucki
- Science Directorate, NASA Ames Research Center, Moffett Field, CA 94035, USA
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11
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12
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THEKEPLERDICHOTOMY AMONG THE M DWARFS: HALF OF SYSTEMS CONTAIN FIVE OR MORE COPLANAR PLANETS. ACTA ACUST UNITED AC 2016. [DOI: 10.3847/0004-637x/816/2/66] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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15
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Becker JC, Vanderburg A, Adams FC, Rappaport SA, Schwengeler HM. WASP-47: A HOT JUPITER SYSTEM WITH TWO ADDITIONAL PLANETS DISCOVERED BY K2. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/2041-8205/812/2/l18] [Citation(s) in RCA: 189] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Welsh WF, Orosz JA, Short DR, Cochran WD, Endl M, Brugamyer E, Haghighipour N, Buchhave LA, Doyle LR, Fabrycky DC, Hinse TC, Kane SR, Kostov V, Mazeh T, Mills SM, Müller TWA, Quarles B, Quinn SN, Ragozzine D, Shporer A, Steffen JH, Tal-Or L, Torres G, Windmiller G, Borucki WJ. KEPLER 453 b—THE 10thKEPLERTRANSITING CIRCUMBINARY PLANET. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/809/1/26] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Swift JJ, Montet BT, Vanderburg A, Morton T, Muirhead PS, Johnson JA. CHARACTERIZING THE COOL KOIs. VIII. PARAMETERS OF THE PLANETS ORBITING
KEPLER
’S COOLEST DWARFS. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0067-0049/218/2/26] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Jontof-Hutter D, Rowe JF, Lissauer JJ, Fabrycky DC, Ford EB. The mass of the Mars-sized exoplanet Kepler-138 b from transit timing. Nature 2015; 522:321-3. [DOI: 10.1038/nature14494] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 04/17/2015] [Indexed: 11/09/2022]
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Crossfield IJM, Petigura E, Schlieder JE, Howard AW, Fulton BJ, Aller KM, Ciardi DR, Lépine S, Barclay T, Pater ID, Kleer KD, Quintana EV, Christiansen JL, Schlafly E, Kaltenegger L, Crepp JR, Henning T, Obermeier C, Deacon N, Weiss LM, Isaacson HT, Hansen BMS, Liu MC, Greene T, Howell SB, Barman T, Mordasini C. A NEARBY M STAR WITH THREE TRANSITING SUPER-EARTHS DISCOVERED BY K2. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/804/1/10] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Batygin K, Laughlin G. Jupiter's decisive role in the inner Solar System's early evolution. Proc Natl Acad Sci U S A 2015; 112:4214-7. [PMID: 25831540 PMCID: PMC4394287 DOI: 10.1073/pnas.1423252112] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The statistics of extrasolar planetary systems indicate that the default mode of planet formation generates planets with orbital periods shorter than 100 days and masses substantially exceeding that of the Earth. When viewed in this context, the Solar System is unusual. Here, we present simulations which show that a popular formation scenario for Jupiter and Saturn, in which Jupiter migrates inward from a > 5 astronomical units (AU) to a ≈ 1.5 AU before reversing direction, can explain the low overall mass of the Solar System's terrestrial planets, as well as the absence of planets with a < 0.4 AU. Jupiter's inward migration entrained s ≳ 10-100 km planetesimals into low-order mean motion resonances, shepherding and exciting their orbits. The resulting collisional cascade generated a planetesimal disk that, evolving under gas drag, would have driven any preexisting short-period planets into the Sun. In this scenario, the Solar System's terrestrial planets formed from gas-starved mass-depleted debris that remained after the primary period of dynamical evolution.
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Affiliation(s)
- Konstantin Batygin
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125; and
| | - Greg Laughlin
- Department of Astronomy & Astrophysics, University of California Observatories/Lick Observatory, University of California, Santa Cruz, CA 95064
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22
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Deck KM, Agol E. MEASUREMENT OF PLANET MASSES WITH TRANSIT TIMING VARIATIONS DUE TO SYNODIC “CHOPPING” EFFECTS. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/802/2/116] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Izidoro A, Raymond SN, Morbidelli A, Hersant F, Pierens A. GAS GIANT PLANETS AS DYNAMICAL BARRIERS TO INWARD-MIGRATING SUPER-EARTHS. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/2041-8205/800/2/l22] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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24
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Campante TL, Barclay T, Swift JJ, Huber D, Adibekyan VZ, Cochran W, Burke CJ, Isaacson H, Quintana EV, Davies GR, Silva Aguirre V, Ragozzine D, Riddle R, Baranec C, Basu S, Chaplin WJ, Christensen-Dalsgaard J, Metcalfe TS, Bedding TR, Handberg R, Stello D, Brewer JM, Hekker S, Karoff C, Kolbl R, Law NM, Lundkvist M, Miglio A, Rowe JF, Santos NC, Van Laerhoven C, Arentoft T, Elsworth YP, Fischer DA, Kawaler SD, Kjeldsen H, Lund MN, Marcy GW, Sousa SG, Sozzetti A, White TR. AN ANCIENT EXTRASOLAR SYSTEM WITH FIVE SUB-EARTH-SIZE PLANETS. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/799/2/170] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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25
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Lee EJ, Chiang E, Ormel CW. MAKE SUPER-EARTHS, NOT JUPITERS: ACCRETING NEBULAR GAS ONTO SOLID CORES AT 0.1 AU AND BEYOND. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/0004-637x/797/2/95] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Morton TD, Winn JN. OBLIQUITIES OFKEPLERSTARS: COMPARISON OF SINGLE- AND MULTIPLE-TRANSIT SYSTEMS. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/0004-637x/796/1/47] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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27
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Schmitt JR, Agol E, Deck KM, Rogers LA, Gazak JZ, Fischer DA, Wang J, Holman MJ, Jek KJ, Margossian C, Omohundro MR, Winarski T, Brewer JM, Giguere MJ, Lintott C, Lynn S, Parrish M, Schawinski K, Schwamb ME, Simpson R, Smith AM. PLANET HUNTERS. VII. DISCOVERY OF A NEW LOW-MASS, LOW-DENSITY PLANET (PH3 C) ORBITING KEPLER-289 WITH MASS MEASUREMENTS OF TWO ADDITIONAL PLANETS (PH3 B AND D). ACTA ACUST UNITED AC 2014. [DOI: 10.1088/0004-637x/795/2/167] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Lissauer JJ, Dawson RI, Tremaine S. Advances in exoplanet science from Kepler. Nature 2014; 513:336-44. [PMID: 25230655 DOI: 10.1038/nature13781] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 07/24/2014] [Indexed: 11/09/2022]
Abstract
Numerous telescopes and techniques have been used to find and study extrasolar planets, but none has been more successful than NASA's Kepler space telescope. Kepler has discovered most of the known exoplanets, the smallest planets to orbit normal stars and the planets most likely to be similar to Earth. Most importantly, Kepler has provided us with our first look at the typical characteristics of planets and planetary systems for planets with sizes as small as, and orbits as large as, those of Earth.
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Affiliation(s)
- Jack J Lissauer
- NASA Ames Research Center, Moffett Field, California 94035, USA
| | - Rebekah I Dawson
- Department of Astronomy, University of California, Berkeley, California 94720, USA
| | - Scott Tremaine
- Institute for Advanced Study, Princeton, New Jersey 08540, USA
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Henderson CB, Gaudi BS, Han C, Skowron J, Penny MT, Nataf D, Gould AP. OPTIMAL SURVEY STRATEGIES AND PREDICTED PLANET YIELDS FOR THE KOREAN MICROLENSING TELESCOPE NETWORK. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/0004-637x/794/1/52] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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31
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Ford EB. Architectures of planetary systems and implications for their formation. Proc Natl Acad Sci U S A 2014; 111:12616-21. [PMID: 24778212 PMCID: PMC4156699 DOI: 10.1073/pnas.1304219111] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Doppler planet searches revealed that many giant planets orbit close to their host star or in highly eccentric orbits. These and subsequent observations inspired new theories of planet formation that invoke gravitation interactions in multiple planet systems to explain the excitation of orbital eccentricities and even short-period giant planets. Recently, NASA's Kepler mission has identified over 300 systems with multiple transiting planet candidates, including many potentially rocky planets. Most of these systems include multiple planets with closely spaced orbits and sizes between that of Earth and Neptune. These systems represent yet another new and unexpected class of planetary systems and provide an opportunity to test the theories developed to explain the properties of giant exoplanets. Presently, we have limited knowledge about such planetary systems, mostly about their sizes and orbital periods. With the advent of long-term, nearly continuous monitoring by Kepler, the method of transit timing variations (TTVs) has blossomed as a new technique for characterizing the gravitational effects of mutual planetary perturbations for hundreds of planets. TTVs can provide precise, but complex, constraints on planetary masses, densities, and orbits, even for planetary systems with faint host stars. In the coming years, astronomers will translate TTV observations into increasingly powerful constraints on the formation and orbital evolution of planetary systems with low-mass planets. Between TTVs, improved Doppler surveys, high-contrast imaging campaigns, and microlensing surveys, astronomers can look forward to a much better understanding of planet formation in the coming decade.
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Affiliation(s)
- Eric B Ford
- Center for Exoplanets and Habitable Worlds, andDepartment of Astronomy and Astrophysics, The Pennsylvania State University, State College, PA 16803
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32
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Abstract
The Kepler Mission is exploring the diversity of planets and planetary systems. Its legacy will be a catalog of discoveries sufficient for computing planet occurrence rates as a function of size, orbital period, star type, and insolation flux. The mission has made significant progress toward achieving that goal. Over 3,500 transiting exoplanets have been identified from the analysis of the first 3 y of data, 100 planets of which are in the habitable zone. The catalog has a high reliability rate (85-90% averaged over the period/radius plane), which is improving as follow-up observations continue. Dynamical (e.g., velocimetry and transit timing) and statistical methods have confirmed and characterized hundreds of planets over a large range of sizes and compositions for both single- and multiple-star systems. Population studies suggest that planets abound in our galaxy and that small planets are particularly frequent. Here, I report on the progress Kepler has made measuring the prevalence of exoplanets orbiting within one astronomical unit of their host stars in support of the National Aeronautics and Space Administration's long-term goal of finding habitable environments beyond the solar system.
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Affiliation(s)
- Natalie M Batalha
- National Aeronautics and Space Administration Ames Research Center, Moffett Field, 94035 CA
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33
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Boley AC, Morris MA, Ford EB. OVERCOMING THE METER BARRIER AND THE FORMATION OF SYSTEMS WITH TIGHTLY PACKED INNER PLANETS (STIPs). ACTA ACUST UNITED AC 2014. [DOI: 10.1088/2041-8205/792/2/l27] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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34
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Lopez ED, Fortney JJ. UNDERSTANDING THE MASS-RADIUS RELATION FOR SUB-NEPTUNES: RADIUS AS A PROXY FOR COMPOSITION. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/0004-637x/792/1/1] [Citation(s) in RCA: 419] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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35
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Abstract
The discovery and characterization of exoplanets have the potential to offer the world one of the most impactful findings ever in the history of astronomy--the identification of life beyond Earth. Life can be inferred by the presence of atmospheric biosignature gases--gases produced by life that can accumulate to detectable levels in an exoplanet atmosphere. Detection will be made by remote sensing by sophisticated space telescopes. The conviction that biosignature gases will actually be detected in the future is moderated by lessons learned from the dozens of exoplanet atmospheres studied in last decade, namely the difficulty in robustly identifying molecules, the possible interference of clouds, and the permanent limitations from a spectrum of spatially unresolved and globally mixed gases without direct surface observations. The vision for the path to assess the presence of life beyond Earth is being established.
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36
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Bodenheimer P, Lissauer JJ. ACCRETION AND EVOLUTION OF ∼2.5M⊕PLANETS WITH VOLUMINOUS H/He ENVELOPES. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/0004-637x/791/2/103] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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37
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Musielak ZE, Quarles B. The three-body problem. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2014; 77:065901. [PMID: 24913140 DOI: 10.1088/0034-4885/77/6/065901] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The three-body problem, which describes three masses interacting through Newtonian gravity without any restrictions imposed on the initial positions and velocities of these masses, has attracted the attention of many scientists for more than 300 years. In this paper, we present a review of the three-body problem in the context of both historical and modern developments. We describe the general and restricted (circular and elliptic) three-body problems, different analytical and numerical methods of finding solutions, methods for performing stability analysis and searching for periodic orbits and resonances. We apply the results to some interesting problems of celestial mechanics. We also provide a brief presentation of the general and restricted relativistic three-body problems, and discuss their astronomical applications.
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Affiliation(s)
- Z E Musielak
- Department of Physics, The University of Texas at Arlington, Arlington, TX 76019, USA
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38
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Stixrude L. Melting in super-earths. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2014; 372:20130076. [PMID: 24664915 DOI: 10.1098/rsta.2013.0076] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We examine the possible extent of melting in rock-iron super-earths, focusing on those in the habitable zone. We consider the energetics of accretion and core formation, the timescale of cooling and its dependence on viscosity and partial melting, thermal regulation via the temperature dependence of viscosity, and the melting curves of rock and iron components at the ultra-high pressures characteristic of super-earths. We find that the efficiency of kinetic energy deposition during accretion increases with planetary mass; considering the likely role of giant impacts and core formation, we find that super-earths probably complete their accretionary phase in an entirely molten state. Considerations of thermal regulation lead us to propose model temperature profiles of super-earths that are controlled by silicate melting. We estimate melting curves of iron and rock components up to the extreme pressures characteristic of super-earth interiors based on existing experimental and ab initio results and scaling laws. We construct super-earth thermal models by solving the equations of mass conservation and hydrostatic equilibrium, together with equations of state of rock and iron components. We set the potential temperature at the core-mantle boundary and at the surface to the local silicate melting temperature. We find that ancient (∼4 Gyr) super-earths may be partially molten at the top and bottom of their mantles, and that mantle convection is sufficiently vigorous to sustain dynamo action over the whole range of super-earth masses.
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Affiliation(s)
- Lars Stixrude
- Department of Earth Sciences, University College London, , Gower St, London WC1E 6BT, UK
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39
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40
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No universal minimum-mass extrasolar nebula: evidence against in situ accretion of systems of hot super-Earths. ACTA ACUST UNITED AC 2014. [DOI: 10.1093/mnrasl/slu011] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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41
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Erkaev NV, Lammer H, Odert P, Kulikov YN, Kislyakova KG, Khodachenko ML, Güdel M, Hanslmeier A, Biernat H. XUV-exposed, non-hydrostatic hydrogen-rich upper atmospheres of terrestrial planets. Part I: atmospheric expansion and thermal escape. ASTROBIOLOGY 2013; 13:1011-29. [PMID: 24251443 PMCID: PMC3865622 DOI: 10.1089/ast.2012.0957] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 09/07/2013] [Indexed: 05/15/2023]
Abstract
The recently discovered low-density "super-Earths" Kepler-11b, Kepler-11f, Kepler-11d, Kepler-11e, and planets such as GJ 1214b represent the most likely known planets that are surrounded by dense H/He envelopes or contain deep H₂O oceans also surrounded by dense hydrogen envelopes. Although these super-Earths are orbiting relatively close to their host stars, they have not lost their captured nebula-based hydrogen-rich or degassed volatile-rich steam protoatmospheres. Thus, it is interesting to estimate the maximum possible amount of atmospheric hydrogen loss from a terrestrial planet orbiting within the habitable zone of late main sequence host stars. For studying the thermosphere structure and escape, we apply a 1-D hydrodynamic upper atmosphere model that solves the equations of mass, momentum, and energy conservation for a planet with the mass and size of Earth and for a super-Earth with a size of 2 R(Earth) and a mass of 10 M(Earth). We calculate volume heating rates by the stellar soft X-ray and extreme ultraviolet radiation (XUV) and expansion of the upper atmosphere, its temperature, density, and velocity structure and related thermal escape rates during the planet's lifetime. Moreover, we investigate under which conditions both planets enter the blow-off escape regime and may therefore experience loss rates that are close to the energy-limited escape. Finally, we discuss the results in the context of atmospheric evolution and implications for habitability of terrestrial planets in general.
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Affiliation(s)
- Nikolai V. Erkaev
- Institute of Computational Modelling, Siberian Division of the Russian Academy of Sciences, Krasnoyarsk, Russian Federation
- Siberian Federal University, Krasnoyarsk, Russian Federation
| | - Helmut Lammer
- Austrian Academy of Sciences, Space Research Institute, Graz, Austria
| | - Petra Odert
- Austrian Academy of Sciences, Space Research Institute, Graz, Austria
- Institute of Physics, University of Graz, Graz, Austria
| | - Yuri N. Kulikov
- Polar Geophysical Institute (PGI), Russian Academy of Sciences, Murmansk, Russian Federation
| | - Kristina G. Kislyakova
- Austrian Academy of Sciences, Space Research Institute, Graz, Austria
- Institute of Physics, University of Graz, Graz, Austria
| | - Maxim L. Khodachenko
- Austrian Academy of Sciences, Space Research Institute, Graz, Austria
- Institute of Nuclear Physics, Moscow State University, Moscow, Russian Federation
| | - Manuel Güdel
- Institute of Astrophysics, University of Vienna, Austria
| | | | - Helfried Biernat
- Austrian Academy of Sciences, Space Research Institute, Graz, Austria
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42
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Kislyakova KG, Lammer H, Holmström M, Panchenko M, Odert P, Erkaev NV, Leitzinger M, Khodachenko ML, Kulikov YN, Güdel M, Hanslmeier A. XUV-exposed, non-hydrostatic hydrogen-rich upper atmospheres of terrestrial planets. Part II: hydrogen coronae and ion escape. ASTROBIOLOGY 2013; 13:1030-48. [PMID: 24283926 PMCID: PMC3865724 DOI: 10.1089/ast.2012.0958] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We studied the interactions between the stellar wind plasma flow of a typical M star, such as GJ 436, and the hydrogen-rich upper atmosphere of an Earth-like planet and a "super-Earth" with a radius of 2 R(Earth) and a mass of 10 M(Earth), located within the habitable zone at ∼0.24 AU. We investigated the formation of extended atomic hydrogen coronae under the influences of the stellar XUV flux (soft X-rays and EUV), stellar wind density and velocity, shape of a planetary obstacle (e.g., magnetosphere, ionopause), and the loss of planetary pickup ions on the evolution of hydrogen-dominated upper atmospheres. Stellar XUV fluxes that are 1, 10, 50, and 100 times higher compared to that of the present-day Sun were considered, and the formation of high-energy neutral hydrogen clouds around the planets due to the charge-exchange reaction under various stellar conditions was modeled. Charge-exchange between stellar wind protons with planetary hydrogen atoms, and photoionization, lead to the production of initially cold ions of planetary origin. We found that the ion production rates for the studied planets can vary over a wide range, from ∼1.0×10²⁵ s⁻¹ to ∼5.3×10³⁰ s⁻¹, depending on the stellar wind conditions and the assumed XUV exposure of the upper atmosphere. Our findings indicate that most likely the majority of these planetary ions are picked up by the stellar wind and lost from the planet. Finally, we estimated the long-time nonthermal ion pickup escape for the studied planets and compared them with the thermal escape. According to our estimates, nonthermal escape of picked-up ionized hydrogen atoms over a planet's lifetime within the habitable zone of an M dwarf varies between ∼0.4 Earth ocean equivalent amounts of hydrogen (EO(H)) to <3 EO(H) and usually is several times smaller in comparison to the thermal atmospheric escape rates.
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Affiliation(s)
- Kristina G. Kislyakova
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
- Institute of Physics, University of Graz, Graz, Austria
| | - Helmut Lammer
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | | | | | - Petra Odert
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
- Institute of Physics, University of Graz, Graz, Austria
| | - Nikolai V. Erkaev
- Institute of Computational Modelling, Siberian Division of the Russian Academy of Sciences, Krasnoyarsk, Russian Federation
| | | | - Maxim L. Khodachenko
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
- SINP, Moscow State University, Moscow, Russian Federation
| | - Yuri N. Kulikov
- Polar Geophysical Institute (PGI), Russian Academy of Sciences, Murmansk, Russian Federation
| | - Manuel Güdel
- Institute of Astrophysics, University of Vienna, Austria
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43
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Lammer H, Blanc M, Benz W, Fridlund M, Foresto VCD, Güdel M, Rauer H, Udry S, Bonnet RM, Falanga M, Charbonneau D, Helled R, Kley W, Linsky J, Elkins-Tanton LT, Alibert Y, Chassefière E, Encrenaz T, Hatzes AP, Lin D, Liseau R, Lorenzen W, Raymond SN. The science of exoplanets and their systems. ASTROBIOLOGY 2013; 13:793-813. [PMID: 24015759 DOI: 10.1089/ast.2013.0997] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A scientific forum on "The Future Science of Exoplanets and Their Systems," sponsored by Europlanet and the International Space Science Institute (ISSI) and co-organized by the Center for Space and Habitability (CSH) of the University of Bern, was held during December 5 and 6, 2012, in Bern, Switzerland. It gathered 24 well-known specialists in exoplanetary, Solar System, and stellar science to discuss the future of the fast-expanding field of exoplanetary research, which now has nearly 1000 objects to analyze and compare and will develop even more quickly over the coming years. The forum discussions included a review of current observational knowledge, efforts for exoplanetary atmosphere characterization and their formation, water formation, atmospheric evolution, habitability aspects, and our understanding of how exoplanets interact with their stellar and galactic environment throughout their history. Several important and timely research areas of focus for further research efforts in the field were identified by the forum participants. These scientific topics are related to the origin and formation of water and its delivery to planetary bodies and the role of the disk in relation to planet formation, including constraints from observations as well as star-planet interaction processes and their consequences for atmosphere-magnetosphere environments, evolution, and habitability. The relevance of these research areas is outlined in this report, and possible themes for future ISSI workshops are identified that may be proposed by the international research community over the coming 2-3 years.
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Affiliation(s)
- Helmut Lammer
- 1 Space Research Institute , Austrian Academy of Sciences, Graz, Austria
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44
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Abstract
Observational surveys for extrasolar planets probe the diverse outcomes of planet formation and evolution. These surveys measure the frequency of planets with different masses, sizes, orbital characteristics, and host star properties. Small planets between the sizes of Earth and Neptune substantially outnumber Jupiter-sized planets. The survey measurements support the core accretion model, in which planets form by the accumulation of solids and then gas in protoplanetary disks. The diversity of exoplanetary characteristics demonstrates that most of the gross features of the solar system are one outcome in a continuum of possibilities. The most common class of planetary system detectable today consists of one or more planets approximately one to three times Earth's size orbiting within a fraction of the Earth-Sun distance.
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Affiliation(s)
- Andrew W Howard
- Institute for Astronomy, University of Hawai'i at Manoa, 2680 Woodlawn Drive, Honolulu, HI 96822, USA.
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45
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Hoyer S, Rojo P, López-Morales M. The Transit Monitoring in the South (TraMoS) project. EPJ WEB OF CONFERENCES 2013. [DOI: 10.1051/epjconf/20134703003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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46
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Carter JA, Agol E, Chaplin WJ, Basu S, Bedding TR, Buchhave LA, Christensen-Dalsgaard J, Deck KM, Elsworth Y, Fabrycky DC, Ford EB, Fortney JJ, Hale SJ, Handberg R, Hekker S, Holman MJ, Huber D, Karoff C, Kawaler SD, Kjeldsen H, Lissauer JJ, Lopez ED, Lund MN, Lundkvist M, Metcalfe TS, Miglio A, Rogers LA, Stello D, Borucki WJ, Bryson S, Christiansen JL, Cochran WD, Geary JC, Gilliland RL, Haas MR, Hall J, Howard AW, Jenkins JM, Klaus T, Koch DG, Latham DW, MacQueen PJ, Sasselov D, Steffen JH, Twicken JD, Winn JN. Kepler-36: A Pair of Planets with Neighboring Orbits and Dissimilar Densities. Science 2012; 337:556-9. [DOI: 10.1126/science.1223269] [Citation(s) in RCA: 310] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Joshua A. Carter
- Hubble Fellow, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
| | - Eric Agol
- Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195, USA
| | - William J. Chaplin
- School of Physics and Astronomy, University of Birmingham, Edgbaston B15 2TT, UK
| | - Sarbani Basu
- Department and Astronomy, Yale University, New Haven, CT 06520, USA
| | - Timothy R. Bedding
- Sydney Institute for Astronomy, School of Physics, University of Sydney, Sydney, Australia and Niels Bohr Institute, Copenhagen University, DK-2100 Copenhagen, Denmark
| | - Lars A. Buchhave
- Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, DK-1350 Copenhagen, Denmark
| | - Jørgen Christensen-Dalsgaard
- Stellar Astrophysics Centre (SAC), Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Katherine M. Deck
- Massachusetts Institute of Technology, Physics Department and Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Yvonne Elsworth
- School of Physics and Astronomy, University of Birmingham, Edgbaston B15 2TT, UK
| | - Daniel C. Fabrycky
- Hubble Fellow, Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USA
| | - Eric B. Ford
- Department of Astronomy, University of Florida, Gainesville, FL 32611–2055, USA
| | - Jonathan J. Fortney
- Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USA
| | - Steven J. Hale
- School of Physics and Astronomy, University of Birmingham, Edgbaston B15 2TT, UK
| | - Rasmus Handberg
- Stellar Astrophysics Centre (SAC), Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Saskia Hekker
- Astronomical Institute “Anton Pannekoek,” University of Amsterdam, Netherlands School of Physics, Amsterdam, Netherlands and Astronomy, University of Birmingham, Edgbaston B15 2TT, UK
| | - Matthew J. Holman
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
| | - Daniel Huber
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Christopher Karoff
- Stellar Astrophysics Centre (SAC), Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Steven D. Kawaler
- Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA
| | - Hans Kjeldsen
- Stellar Astrophysics Centre (SAC), Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | | | - Eric D. Lopez
- Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USA
| | - Mikkel N. Lund
- Stellar Astrophysics Centre (SAC), Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Mia Lundkvist
- Stellar Astrophysics Centre (SAC), Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | | | - Andrea Miglio
- School of Physics and Astronomy, University of Birmingham, Edgbaston B15 2TT, UK
| | - Leslie A. Rogers
- Massachusetts Institute of Technology, Physics Department and Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Dennis Stello
- Sydney Institute for Astronomy, School of Physics, University of Sydney, Sydney, Australia and Niels Bohr Institute, Copenhagen University, DK-2100 Copenhagen, Denmark
| | | | - Steve Bryson
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | | | - William D. Cochran
- McDonald Observatory, University of Texas at Austin, Austin, TX 78712, USA
| | - John C. Geary
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
| | - Ronald L. Gilliland
- Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, University Park, PA 16802, USA
| | | | - Jennifer Hall
- Orbital Science Corporation/NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Andrew W. Howard
- Department of Astronomy, University of California, Berkeley, CA 94720, USA
| | - Jon M. Jenkins
- SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Todd Klaus
- Orbital Science Corporation/NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - David G. Koch
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - David W. Latham
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
| | | | - Dimitar Sasselov
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
| | - Jason H. Steffen
- Fermilab Center for Particle Astrophysics, Post Office Box 500, Batavia, IL 60510, USA
| | - Joseph D. Twicken
- SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Joshua N. Winn
- Massachusetts Institute of Technology, Physics Department and Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
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Planets on the spot. Nature 2012; 487:434-5. [DOI: 10.1038/487434a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Buchhave LA, Latham DW, Johansen A, Bizzarro M, Torres G, Rowe JF, Batalha NM, Borucki WJ, Brugamyer E, Caldwell C, Bryson ST, Ciardi DR, Cochran WD, Endl M, Esquerdo GA, Ford EB, Geary JC, Gilliland RL, Hansen T, Isaacson H, Laird JB, Lucas PW, Marcy GW, Morse JA, Robertson P, Shporer A, Stefanik RP, Still M, Quinn SN. An abundance of small exoplanets around stars with a wide range of metallicities. Nature 2012; 486:375-7. [DOI: 10.1038/nature11121] [Citation(s) in RCA: 472] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 04/05/2012] [Indexed: 11/09/2022]
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Migration-induced architectures of planetary systems. ORIGINS LIFE EVOL B 2012; 42:113-42. [PMID: 22684330 PMCID: PMC3389249 DOI: 10.1007/s11084-012-9287-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 04/05/2012] [Indexed: 11/24/2022]
Abstract
The recent increase in number of known multi-planet systems gives a unique opportunity to study the processes responsible for planetary formation and evolution. Special attention is given to the occurrence of mean-motion resonances, because they carry important information about the history of the planetary systems. At the early stages of the evolution, when planets are still embedded in a gaseous disc, the tidal interactions between the disc and planets cause the planetary orbital migration. The convergent differential migration of two planets embedded in a gaseous disc may result in the capture into a mean-motion resonance. The orbital migration taking place during the early phases of the planetary system formation may play an important role in shaping stable planetary configurations. An understanding of this stage of the evolution will provide insight on the most frequently formed architectures, which in turn are relevant for determining the planet habitability. The aim of this paper is to present the observational properties of these planetary systems which contain confirmed or suspected resonant configurations. A complete list of known systems with such configurations is given. This list will be kept by us updated from now on and it will be a valuable reference for studying the dynamics of extrasolar systems and testing theoretical predictions concerned with the origin and the evolution of planets, which are the most plausible places for existence and development of life.
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Abstract
The Kepler space telescope can determine the mass and orbital period of unseen planets orbiting distant stars.
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Affiliation(s)
- Norman W. Murray
- Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8, Canada
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