Abstract

At a distance of 1.295 parsecs1, the red dwarf Proxima Centauri (α Centauri C, GL 551, HIP 70890 or simply Proxima) is the Sun’s closest stellar neighbour and one of the best-studied low-mass stars. It has an effective temperature of only around 3,050 kelvin, a luminosity of 0.15 per cent of that of the Sun, a measured radius of 14 per cent of the radius of the Sun2 and a mass of about 12 per cent of the mass of the Sun. Although Proxima is considered a moderately active star, its rotation period is about 83 days (ref. 3) and its quiescent activity levels and X-ray luminosity4 are comparable to those of the Sun. Here we report observations that reveal the presence of a small planet with a minimum mass of about 1.3 Earth masses orbiting Proxima with a period of approximately 11.2 days at a semi-major-axis distance of around 0.05 astronomical units. Its equilibrium temperature is within the range where water could be liquid on its surface5.

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Acknowledgements

We thank E. Gerlach, R. Street and U. Seemann for their support to the science preparations. We thank P. Micakovic, M. M. Mutter (QMUL), R. Ivison, G. Hussain, I. Saviane, O. Sandu, L. L. Christensen, R. Hook and the personnel at La Silla (ESO) for making the PRD campaign possible. The authors acknowledge support from the following funding grants: Leverhulme Trust/UK RPG-2014-281 (H.R.A.J., G.A.-E. and M.T.); MINECO/Spain AYA-2014-54348-C3-1-R (P.J.A., C.R.-L., Z.M.B. and E.R.); MINECO/Spain ESP2014-54362-P (M.J.L.-G.); MINECO/Spain AYA-2014-56637-C2-1-P (J.L.O. and N.M.); J.A./Spain 2012-FQM1776 (J.L.O. and N.M.); CATA-Basal/Chile PB06 Conicyt (J.S.J.); Fondecyt/Chile project #1161218 (J.S.J.); STFC/UK ST/M001008/1 (R.P.N., G.A.L.C. and G.A.-E.); STFC/UK ST/L000776/1 (J.B.); ERC/EU Starting Grant #279347 (A.R., L.F.S. and S.V.J.); DFG/Germany Research Grants RE 1664/9-2 (A.R.); RE 1664/12-1 (M.Z.); DFG/Germany Colloborative Research Center 963 (C.J.M. and S.D.); DFG/Germany Research Training Group 1351 (L.F.S.); and NSF/USA grant AST-1313075 (M.E.). Study based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programmes 096.C-0082 and 191.C-0505. Observations were obtained with ASH2, which is supported by the Instituto de Astrofísica de Andalucía and Astroimagen. This work makes use of observations from the LCOGT network. We acknowledge the effort of the UVES/M-dwarf and the HARPS/Geneva teams, who obtained a substantial amount of the data used in this work.

Author information

Affiliations

  1. School of Physics and Astronomy, Queen Mary University of London, 327 Mile End Road, London E1 4NS, UK

    • Guillem Anglada-Escudé
    • , Gavin A. L. Coleman
    • , Richard P. Nelson
    • , Sijme-Jan Paardekooper
    •  & John P. Strachan
  2. Instituto de Astrofísica de Andalucía – Consejo Superior de Investigaciones Científicas, Glorieta de la Astronomía S/N, E-18008 Granada, Spain

    • Pedro J. Amado
    • , Zaira M. Berdiñas
    • , Marίa J. López-González
    • , Nicolás Morales
    • , José L. Ortiz
    • , Eloy Rodríguez
    •  & Cristina Rodrίguez-López
  3. Department of Physical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA, UK

    • John Barnes
  4. Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Road NW, Washington DC 20015, USA

    • R. Paul Butler
  5. Astroimagen, C. Abad y Lasierra, 58 Bis, 6-2, 07800 Ibiza, Spain

    • Ignacio de la Cueva
  6. Institut für Astrophysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany

    • Stefan Dreizler
    • , Benjamin Giesers
    • , Sandra V. Jeffers
    • , Christopher J. Marvin
    • , Ansgar Reiners
    • , Luis F. Sarmiento
    •  & Mathias Zechmeister
  7. McDonald Observatory, the University of Texas at Austin, 2515 Speedway, C1400, Austin, Texas 78712, USA

    • Michael Endl
  8. Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago, Chile

    • James S. Jenkins
  9. Centre for Astrophysics Research, Science & Technology Research Institute, University of Hertfordshire, Hatfield AL10 9AB, UK

    • Hugh R. A. Jones
    •  & Mikko Tuomi
  10. Warsaw University Observatory, Aleje Ujazdowskie 4, Warszawa, Poland

    • Marcin Kiraga
  11. Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany

    • Martin Kürster
  12. Laboratoire Univers et Particules de Montpellier, Université de Montpellier, Place E. Bataillon—CC 72, 34095 Montpellier Cédex 05, France

    • Julien Morin
  13. Department of Earth and Planetary Sciences, Weizmann Institute of Science, 234 Herzl Street, Rehovot 76100, Israel

    • Aviv Ofir
  14. Astronomisches Rechen-Institut, Mönchhofstrasse 12–14, 69120 Heidelberg, Germany

    • Yiannis Tsapras

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Contributions

In the author list, after G.A.-E., the authors are listed in alphabetical order. G.A.-E. led the PRD campaign, observing proposals and organized the manuscript. P.J.A. led observing proposals and organized and supported the Instituto de Astrofisica de Andalucía team through research grants. M.T. obtained the early signal detections and most of the Bayesian analyses. J.S.J., J.B., Z.M.B. and H.R.A.J. participated in the analyses and obtained activity measurements. Z.M.B. also led observing proposals. H.R.A.J. funded several co-authors via research grants. M. Kuerster and M.E. provided the extracted UVES spectra, and R.P.B. re-derived radial velocity measurements. C.R.-L. coordinated photometric follow-up campaigns. E.R. led the ASH2 team and related reductions (M.J.L.-G., I.d.l.C., J.L.O. and N.M.). Y.T. led the LCOGT proposals, campaign and reductions. M.Z. obtained observations and performed analyses on HARPS and UVES spectra. A.O. analysed time series and transit searches. J.M., S.V.J. and A.R. analysed stellar activity data. A.R. funded several co-authors via research grants. R.P.N., G.A.L.C., S.-J.P., S.D. and B.G. did dynamical studies and studied the planet formation context. M. Kiraga provided early access to time series from the ASAS survey. C.J.M. and L.F.S. participated in the HARPS campaigns. All authors contributed to the preparation of observing proposals and the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Guillem Anglada-Escudé.

Reviewer Information

Nature thanks A. Hatzes and D. Queloz for their contribution to the peer review of this work.

Extended data

Supplementary information

Zip files

  1. 1.

    Supplementary Data

    This zipped file contains the time-series used in the paper. All time-series are given as plain ASCII/CSV files (columns separated by commas) and follow the same format. See the README file within the zip folder for details.