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Jeffers SV, Dreizler S, Barnes JR, Haswell CA, Nelson RP, Rodríguez E, López-González MJ, Morales N, Luque R, Zechmeister M, Vogt SS, Jenkins JS, Palle E, Berdi Ñas ZM, Coleman GAL, Díaz MR, Ribas I, Jones HRA, Butler RP, Tinney CG, Bailey J, Carter BD, O'Toole S, Wittenmyer RA, Crane JD, Feng F, Shectman SA, Teske J, Reiners A, Amado PJ, Anglada-Escudé G. A multiplanet system of super-Earths orbiting the brightest red dwarf star GJ 887. Science 2020; 368:1477-1481. [PMID: 32587019 DOI: 10.1126/science.aaz0795] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 05/12/2020] [Indexed: 11/02/2022]
Abstract
The closet exoplanets to the Sun provide opportunities for detailed characterization of planets outside the Solar System. We report the discovery, using radial velocity measurements, of a compact multiplanet system of super-Earth exoplanets orbiting the nearby red dwarf star GJ 887. The two planets have orbital periods of 9.3 and 21.8 days. Assuming an Earth-like albedo, the equilibrium temperature of the 21.8-day planet is ~350 kelvin. The planets are interior to, but close to the inner edge of, the liquid-water habitable zone. We also detect an unconfirmed signal with a period of ~50 days, which could correspond to a third super-Earth in a more temperate orbit. Our observations show that GJ 887 has photometric variability below 500 parts per million, which is unusually quiet for a red dwarf.
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Affiliation(s)
- S V Jeffers
- Institut für Astrophysik, Georg-August-UniversitÄt, 37077 Göttingen, Germany.
| | - S Dreizler
- Institut für Astrophysik, Georg-August-UniversitÄt, 37077 Göttingen, Germany
| | - J R Barnes
- School of Physical Sciences, The Open University, Milton Keynes MK7 6AA, UK
| | - C A Haswell
- School of Physical Sciences, The Open University, Milton Keynes MK7 6AA, UK
| | - R P Nelson
- School of Physics and Astronomy, Queen Mary University of London, London E1 4NS, UK
| | - E Rodríguez
- Instituto de Astrofísica de Andalucía, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - M J López-González
- Instituto de Astrofísica de Andalucía, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - N Morales
- Instituto de Astrofísica de Andalucía, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - R Luque
- Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain.,Departamento de Astrofísica, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain
| | - M Zechmeister
- Institut für Astrophysik, Georg-August-UniversitÄt, 37077 Göttingen, Germany
| | - S S Vogt
- University of California/Lick Observatory, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - J S Jenkins
- Departamento de Astronomia, Universidad de Chile, Santiago, Chile.,Centro de Astrofísica y Tecnologías Afines, Santiago, Chile
| | - E Palle
- Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain.,Departamento de Astrofísica, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain
| | - Z M Berdi Ñas
- Departamento de Astronomia, Universidad de Chile, Santiago, Chile
| | - G A L Coleman
- School of Physics and Astronomy, Queen Mary University of London, London E1 4NS, UK.,Physikalisches Institut, UniversitÄt Bern, 3012 Bern, Switzerland
| | - M R Díaz
- Departamento de Astronomia, Universidad de Chile, Santiago, Chile
| | - I Ribas
- Institut de Ciències de l'Espai, Consejo Superior de Investigaciones Científicas, Campus Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain.,Istitut d'Estudis Espacials de Catalunya, E-08034 Barcelona, Spain
| | - H R A Jones
- Centre for Astrophysics Research, University of Hertfordshire, Hatfield AL10 9AB, UK
| | - R P Butler
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC 20015, USA
| | - C G Tinney
- Exoplanetary Science at University of New South Wales, School of Physics, University of New South Wales, Sydney, NSW 2052, Australia
| | - J Bailey
- Exoplanetary Science at University of New South Wales, School of Physics, University of New South Wales, Sydney, NSW 2052, Australia
| | - B D Carter
- Centre for Astrophysics, University of Southern Queensland, Springfield Central, QLD 4300, Australia
| | - S O'Toole
- Australian Astronomical Optics, Macquarie University, North Ryde, NSW 2113, Australia
| | - R A Wittenmyer
- Centre for Astrophysics, University of Southern Queensland, Toowoomba, QLD 4350, Australia
| | - J D Crane
- The Observatories of the Carnegie Institution for Science, Pasadena, CA 91101, USA
| | - F Feng
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC 20015, USA
| | - S A Shectman
- The Observatories of the Carnegie Institution for Science, Pasadena, CA 91101, USA
| | - J Teske
- The Observatories of the Carnegie Institution for Science, Pasadena, CA 91101, USA
| | - A Reiners
- Institut für Astrophysik, Georg-August-UniversitÄt, 37077 Göttingen, Germany
| | - P J Amado
- Instituto de Astrofísica de Andalucía, Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain
| | - G Anglada-Escudé
- School of Physics and Astronomy, Queen Mary University of London, London E1 4NS, UK.,Institut de Ciències de l'Espai, Consejo Superior de Investigaciones Científicas, Campus Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain.,Istitut d'Estudis Espacials de Catalunya, E-08034 Barcelona, Spain
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Ribas I, Tuomi M, Reiners A, Butler RP, Morales JC, Perger M, Dreizler S, Rodríguez-López C, González Hernández JI, Rosich A, Feng F, Trifonov T, Vogt SS, Caballero JA, Hatzes A, Herrero E, Jeffers SV, Lafarga M, Murgas F, Nelson RP, Rodríguez E, Strachan JBP, Tal-Or L, Teske J, Toledo-Padrón B, Zechmeister M, Quirrenbach A, Amado PJ, Azzaro M, Béjar VJS, Barnes JR, Berdiñas ZM, Burt J, Coleman G, Cortés-Contreras M, Crane J, Engle SG, Guinan EF, Haswell CA, Henning T, Holden B, Jenkins J, Jones HRA, Kaminski A, Kiraga M, Kürster M, Lee MH, López-González MJ, Montes D, Morin J, Ofir A, Pallé E, Rebolo R, Reffert S, Schweitzer A, Seifert W, Shectman SA, Staab D, Street RA, Suárez Mascareño A, Tsapras Y, Wang SX, Anglada-Escudé G. A candidate super-Earth planet orbiting near the snow line of Barnard’s star. Nature 2018; 563:365-368. [DOI: 10.1038/s41586-018-0677-y] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 10/01/2018] [Indexed: 11/09/2022]
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Hallinan G, Littlefair SP, Cotter G, Bourke S, Harding LK, Pineda JS, Butler RP, Golden A, Basri G, Doyle JG, Kao MM, Berdyugina SV, Kuznetsov A, Rupen MP, Antonova A. Magnetospherically driven optical and radio aurorae at the end of the stellar main sequence. Nature 2015. [PMID: 26223623 DOI: 10.1038/nature14619] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Aurorae are detected from all the magnetized planets in our Solar System, including Earth. They are powered by magnetospheric current systems that lead to the precipitation of energetic electrons into the high-latitude regions of the upper atmosphere. In the case of the gas-giant planets, these aurorae include highly polarized radio emission at kilohertz and megahertz frequencies produced by the precipitating electrons, as well as continuum and line emission in the infrared, optical, ultraviolet and X-ray parts of the spectrum, associated with the collisional excitation and heating of the hydrogen-dominated atmosphere. Here we report simultaneous radio and optical spectroscopic observations of an object at the end of the stellar main sequence, located right at the boundary between stars and brown dwarfs, from which we have detected radio and optical auroral emissions both powered by magnetospheric currents. Whereas the magnetic activity of stars like our Sun is powered by processes that occur in their lower atmospheres, these aurorae are powered by processes originating much further out in the magnetosphere of the dwarf star that couple energy into the lower atmosphere. The dissipated power is at least four orders of magnitude larger than what is produced in the Jovian magnetosphere, revealing aurorae to be a potentially ubiquitous signature of large-scale magnetospheres that can scale to luminosities far greater than those observed in our Solar System. These magnetospheric current systems may also play a part in powering some of the weather phenomena reported on brown dwarfs.
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Affiliation(s)
- G Hallinan
- California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA
| | - S P Littlefair
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, UK
| | - G Cotter
- Department of Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK
| | - S Bourke
- California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA
| | - L K Harding
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-0899, USA
| | - J S Pineda
- California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA
| | - R P Butler
- Centre for Astronomy, National University of Ireland, Galway, University Road, Galway, Republic of Ireland
| | - A Golden
- Department of Mathematical Sciences, Yeshiva University, New York, New York 10033, USA
| | - G Basri
- Astronomy Department, University of California, Campbell Hall, Berkeley, California 94720, USA
| | - J G Doyle
- Armagh Observatory, College Hill, Armagh BT61 9DG, UK
| | - M M Kao
- California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA
| | - S V Berdyugina
- Kiepenheuer Institut für Sonnenphysik, Schöneckstrasse 6, D-79104 Freiburg, Germany
| | - A Kuznetsov
- Institute of Solar-Terrestrial Physics, Irkutsk 664033, Russia
| | - M P Rupen
- National Radio Astronomy Observatory, PO Box O, Socorro, New Mexico 87801, USA
| | - A Antonova
- Department of Astronomy, Faculty of Physics, St Kliment Ohridski University of Sofia, 5 James Bourchier Boulevard, 1164 Sofia, Bulgaria
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