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A candidate super-Earth planet orbiting near the snow line of Barnard's star.
Ribas, I; Tuomi, M; Reiners, A; Butler, R P; Morales, J C; Perger, M; Dreizler, S; Rodríguez-López, C; González Hernández, J I; Rosich, A; Feng, F; Trifonov, T; Vogt, S S; Caballero, J A; Hatzes, A; Herrero, E; Jeffers, S V; Lafarga, M; Murgas, F; Nelson, R P; Rodríguez, E; Strachan, J B P; Tal-Or, L; Teske, J; Toledo-Padrón, B; Zechmeister, M; Quirrenbach, A; Amado, P J; Azzaro, M; Béjar, V J S; Barnes, J R; Berdiñas, Z M; Burt, J; Coleman, G; Cortés-Contreras, M; Crane, J; Engle, S G; Guinan, E F; Haswell, C A; Henning, Th; Holden, B; Jenkins, J; Jones, H R A; Kaminski, A; Kiraga, M; Kürster, M; Lee, M H; López-González, M J; Montes, D; Morin, J.
Afiliação
  • Ribas I; Institut de Ciències de l'Espai (ICE, CSIC), Campus UAB, Bellaterra, Spain. iribas@ice.cat.
  • Tuomi M; Institut d'Estudis Espacials de Catalunya (IEEC), Barcelona, Spain. iribas@ice.cat.
  • Reiners A; Centre for Astrophysics Research, University of Hertfordshire, Hatfield, UK.
  • Butler RP; Institut für Astrophysik Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany.
  • Morales JC; Department of Terrestrial Magnetism, Carnegie Institution for Science, Washington, DC, USA.
  • Perger M; Institut de Ciències de l'Espai (ICE, CSIC), Campus UAB, Bellaterra, Spain.
  • Dreizler S; Institut d'Estudis Espacials de Catalunya (IEEC), Barcelona, Spain.
  • Rodríguez-López C; Institut de Ciències de l'Espai (ICE, CSIC), Campus UAB, Bellaterra, Spain.
  • González Hernández JI; Institut d'Estudis Espacials de Catalunya (IEEC), Barcelona, Spain.
  • Rosich A; Institut für Astrophysik Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany.
  • Feng F; Instituto de Astrofísica de Andalucía (IAA, CSIC), Granada, Spain.
  • Trifonov T; Instituto de Astrofísica de Canarias (IAC), La Laguna, Spain.
  • Vogt SS; Universidad de La Laguna (ULL), Departamento de Astrofísica, La Laguna, Spain.
  • Caballero JA; Institut de Ciències de l'Espai (ICE, CSIC), Campus UAB, Bellaterra, Spain.
  • Hatzes A; Institut d'Estudis Espacials de Catalunya (IEEC), Barcelona, Spain.
  • Herrero E; Centre for Astrophysics Research, University of Hertfordshire, Hatfield, UK.
  • Jeffers SV; Max-Planck-Institut für Astronomie, Heidelberg, Germany.
  • Lafarga M; UCO/Lick Observatory, University of California at Santa Cruz, Santa Cruz, CA, USA.
  • Murgas F; Centro de Astrobiología, CSIC-INTA, ESAC, Villanueva de la Cañada, Spain.
  • Nelson RP; Thüringer Landessternwarte, Tautenburg, Germany.
  • Rodríguez E; Institut de Ciències de l'Espai (ICE, CSIC), Campus UAB, Bellaterra, Spain.
  • Strachan JBP; Institut d'Estudis Espacials de Catalunya (IEEC), Barcelona, Spain.
  • Tal-Or L; Institut für Astrophysik Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany.
  • Teske J; Institut de Ciències de l'Espai (ICE, CSIC), Campus UAB, Bellaterra, Spain.
  • Toledo-Padrón B; Institut d'Estudis Espacials de Catalunya (IEEC), Barcelona, Spain.
  • Zechmeister M; Instituto de Astrofísica de Canarias (IAC), La Laguna, Spain.
  • Quirrenbach A; Universidad de La Laguna (ULL), Departamento de Astrofísica, La Laguna, Spain.
  • Amado PJ; School of Physics and Astronomy, Queen Mary University of London, London, UK.
  • Azzaro M; Instituto de Astrofísica de Andalucía (IAA, CSIC), Granada, Spain.
  • Béjar VJS; School of Physics and Astronomy, Queen Mary University of London, London, UK.
  • Barnes JR; Institut für Astrophysik Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany.
  • Berdiñas ZM; School of Geosciences, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Tel Aviv, Israel.
  • Burt J; Department of Terrestrial Magnetism, Carnegie Institution for Science, Washington, DC, USA.
  • Coleman G; Instituto de Astrofísica de Canarias (IAC), La Laguna, Spain.
  • Cortés-Contreras M; Universidad de La Laguna (ULL), Departamento de Astrofísica, La Laguna, Spain.
  • Crane J; Institut für Astrophysik Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany.
  • Engle SG; Landessternwarte, Zentrum für Astronomie der Universität Heidelberg, Heidelberg, Germany.
  • Guinan EF; Instituto de Astrofísica de Andalucía (IAA, CSIC), Granada, Spain.
  • Haswell CA; Centro Astronómico Hispano-Alemán (CSIC-MPG), Observatorio Astronómico de Calar Alto, Gérgal, Spain.
  • Henning T; Instituto de Astrofísica de Canarias (IAC), La Laguna, Spain.
  • Holden B; Universidad de La Laguna (ULL), Departamento de Astrofísica, La Laguna, Spain.
  • Jenkins J; School of Physical Sciences, The Open University, Milton Keynes, UK.
  • Jones HRA; Departamento de Astronomía, Universidad de Chile, Santiago, Chile.
  • Kaminski A; Kavli Institute, Massachusetts Institute of Technology, Cambridge, MA, USA.
  • Kiraga M; Physikalisches Institut, Universität Bern, Bern, Switzerland.
  • Kürster M; Centro de Astrobiología, CSIC-INTA, ESAC, Villanueva de la Cañada, Spain.
  • Lee MH; The Observatories, Carnegie Institution for Science, Pasadena, CA, USA.
  • López-González MJ; Department of Astrophysics and Planetary Science, Villanova University, Villanova, PA, USA.
  • Montes D; Department of Astrophysics and Planetary Science, Villanova University, Villanova, PA, USA.
  • Morin J; School of Physical Sciences, The Open University, Milton Keynes, UK.
Nature ; 563(7731): 365-368, 2018 11.
Article em En | MEDLINE | ID: mdl-30429552
Barnard's star is a red dwarf, and has the largest proper motion (apparent motion across the sky) of all known stars. At a distance of 1.8 parsecs1, it is the closest single star to the Sun; only the three stars in the α Centauri system are closer. Barnard's star is also among the least magnetically active red dwarfs known2,3 and has an estimated age older than the Solar System. Its properties make it a prime target for planetary searches; various techniques with different sensitivity limits have been used previously, including radial-velocity imaging4-6, astrometry7,8 and direct imaging9, but all ultimately led to negative or null results. Here we combine numerous measurements from high-precision radial-velocity instruments, revealing the presence of a low-amplitude periodic signal with a period of 233 days. Independent photometric and spectroscopic monitoring, as well as an analysis of instrumental systematic effects, suggest that this signal is best explained as arising from a planetary companion. The candidate planet around Barnard's star is a cold super-Earth, with a minimum mass of 3.2 times that of Earth, orbiting near its snow line (the minimum distance from the star at which volatile compounds could condense). The combination of all radial-velocity datasets spanning 20 years of measurements additionally reveals a long-term modulation that could arise from a stellar magnetic-activity cycle or from a more distant planetary object. Because of its proximity to the Sun, the candidate planet has a maximum angular separation of 220 milliarcseconds from Barnard's star, making it an excellent target for direct imaging and astrometric observations in the future.

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Idioma: En Revista: Nature Ano de publicação: 2018 Tipo de documento: Article País de afiliação: Espanha

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Idioma: En Revista: Nature Ano de publicação: 2018 Tipo de documento: Article País de afiliação: Espanha