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Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1 - Nature

  • ️Queloz, Didier
  • ️Thu Feb 23 2017

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Acknowledgements

This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. The material presented here is based on work supported in part by NASA under contract no. NNX15AI75G. TRAPPIST-South is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant FRFC 2.5.594.09.F, with the participation of the Swiss National Science Foundation (FNS/SNSF). TRAPPIST-North is a project funded by the University of Liège, and performed in collaboration with Cadi Ayyad University of Marrakesh. The research leading to these results has received funding from the European Research Council (ERC) under the FP/2007-2013 ERC grant agreement no. 336480, and under the H2020 ERC grant agreement no. 679030; and from an Actions de Recherche Concertée (ARC) grant, financed by the Wallonia–Brussels Federation. The VLT data used in this work were taken under program 296.C-5010(A). UKIRT is supported by NASA and operated under an agreement among the University of Hawaii, the University of Arizona, and Lockheed Martin Advanced Technology Center; operations are enabled through the cooperation of the East Asian Observatory. The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University (JMU) in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, with financial support from the UK Science and Technology Facilities Council. This paper uses observations made at the South African Astronomical Observatory (SAAO). M.G., E.J. and V.V.G. are F.R.S.-FNRS research associates. B.-O.D. acknowledges support from the Swiss National Science Foundation in the form of a SNSF Professorship (PP00P2_163967). E.A. acknowledges support from National Science Foundation (NSF) grant AST-1615315, and NASA grants NNX13AF62G and NNH05ZDA001C. E.B. acknowledges that this work is part of the F.R.S.-FNRS ExtraOrDynHa research project and acknowledges funding by the European Research Council through ERC grant SPIRE 647383. S.N.R. thanks the Agence Nationale pour la Recherche (ANR) for support via grant ANR-13-BS05-0003-002 (project MOJO). D.L.H. acknowledges financial support from the UK Science and Technology Facilities Council. The authors thank C. Owen, C. Wolf and the rest of the SkyMapper team for their attempts to monitor the star from Australia; from UKIRT, the director R. Green and the staff scientists W. Varricatt and T. Kerr; the ESO staff at Paranal for their support with the HAWK-I observations; JMU and their flexibility as regards the Liverpool Telescope schedule, which allowed us to search actively for the planets, and to extend our time allocation in the face of amazing results; for the William Herschel Telescope, C. Fariña, F. Riddick, F. Jímenez and O. Vaduvescu for their help and kindness during observations; and for SAAO, the telescopes operations manager R. Sefako for his support.

Author information

Authors and Affiliations

  1. Space Sciences, Technologies and Astrophysics Research (STAR) Institute, Université de Liège, Allée du 6 Août 19C, Bat. B5C, Liège, 4000, Belgium

    Michaël Gillon, Emmanuël Jehin, Artem Burdanov, Laetitia Delrez, Catarina S. Fernandes, Valérie Van Grootel & Pierre Magain

  2. Institute of Astronomy, Madingley Road, Cambridge, CB3 0HA, UK

    Amaury H. M. J. Triaud

  3. University of Bern, Center for Space and Habitability, Sidlerstrasse 5, Bern, CH-3012, Switzerland

    Brice-Olivier Demory

  4. Cavendish Laboratory, JJ Thomson Avenue, Cambridge, CB3 0HE, UK

    Brice-Olivier Demory, Laetitia Delrez & Didier Queloz

  5. Astronomy Department, University of Washington, Seattle, 98195, Washington, USA

    Eric Agol

  6. NASA Astrobiology Institute’s Virtual Planetary Laboratory, Seattle, 98195, Washington, USA

    Eric Agol

  7. Department of Geological and Planetary Sciences, California Institute of Technology, Pasadena, 91125, California, USA

    Katherine M. Deck

  8. NASA Johnson Space Center, 2101 NASA Parkway, Houston, 77058, Texas, USA

    Susan M. Lederer

  9. Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, 02139, Massachusetts, USA

    Julien de Wit

  10. Spitzer Science Center, California Institute of Technology, 1200 E California Boulevard, Mail Code 314-6, Pasadena, 91125, California, USA

    James G. Ingalls & Sean J. Carey

  11. Department of Mathematics, NaXys, University of Namur, 8 Rempart de la Vierge, Namur, 5000, Belgium

    Emeline Bolmont

  12. Laboratoire AIM Paris-Saclay, CEA/DRF–CNRS–Univ. Paris Diderot - IRFU/SAp, Centre de Saclay, Gif-sur-Yvette, F- 91191, Cedex, France

    Emeline Bolmont

  13. Laboratoire d'astrophysique de Bordeaux, Université Bordeaux, CNRS, B18N, Allée Geoffroy Saint-Hilaire, Pessac, F-33615, France

    Jeremy Leconte, Sean N. Raymond & Franck Selsis

  14. Laboratoire de Météorologie Dynamique, Sorbonne Universités, UPMC Univ Paris 06, CNRS, 4 Place Jussieu, Paris, 75005, France

    Martin Turbet

  15. Laboratoire LPHEA, Oukaimeden Observatory, Cadi Ayyad University/FSSM, Marrakesh, BP 2390, Morocco

    Khalid Barkaoui & Zouhair Benkhaldoun

  16. Center for Astrophysics and Space Science, University of California San Diego, La Jolla, 92093, California, USA

    Adam Burgasser

  17. Department of Physics and Astronomy, Leicester Institute for Space and Earth Observation, University of Leicester, Leicester, LE1 7RH, UK

    Matthew R. Burleigh & Aleksander Chaushev

  18. Astrophysics Research Institute, Liverpool John Moores University, Liverpool, L3 5RF, UK

    Chris M. Copperwheat

  19. Jeremiah Horrocks Institute, University of Central Lancashire, Preston, PR1 2HE, UK

    Daniel L. Holdsworth

  20. South African Astronomical Observatory, PO Box 9, Observatory, 7935, South Africa

    Enrico J. Kotze

  21. Space and Astronomy Department, Faculty of Science, King Abdulaziz University, Jeddah, 21589, Saudi Arabia

    Yaseen Almleaky

  22. King Abdullah Centre for Crescent Observations and Astronomy, Makkah Clock, Mecca, 24231, Saudi Arabia

    Yaseen Almleaky

  23. Observatoire de Genève, Université de Genève, 51 chemin des Maillettes, CH-1290 Sauverny, Switzerland

    Didier Queloz

Authors

  1. Michaël Gillon

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  2. Amaury H. M. J. Triaud

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  3. Brice-Olivier Demory

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  4. Emmanuël Jehin

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  5. Eric Agol

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  6. Katherine M. Deck

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  7. Susan M. Lederer

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  8. Julien de Wit

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  9. Artem Burdanov

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  10. James G. Ingalls

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  11. Emeline Bolmont

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  12. Jeremy Leconte

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  13. Sean N. Raymond

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  14. Franck Selsis

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  15. Martin Turbet

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  16. Khalid Barkaoui

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  17. Adam Burgasser

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  18. Matthew R. Burleigh

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  19. Sean J. Carey

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  20. Aleksander Chaushev

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  21. Chris M. Copperwheat

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  22. Laetitia Delrez

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  23. Catarina S. Fernandes

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  24. Daniel L. Holdsworth

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  25. Enrico J. Kotze

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  26. Valérie Van Grootel

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  27. Yaseen Almleaky

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  28. Zouhair Benkhaldoun

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  29. Pierre Magain

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  30. Didier Queloz

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Contributions

M.G. leads the ultracool dwarf transit survey that uses the TRAPPIST telescope and led the photometric follow-up of the star TRAPPIST-1; he also planned and analysed most of the observations, led their scientific exploitation, and wrote most of the manuscript. A.H.M.J.T. led the observational campaign using the La Palma telescopes (the Liverpool Telescope, LT, and William Herschel Telescope, WHT). C.M.C. managed the scheduling of the LT observations, and Ar.B. performed the photometric analysis of the resulting LT and WHT images. B.-O.D. led the TTV/dynamical simulations. E.A. and K.M.D. performed independent analyses of the transit timings. J.G.I. and S.J.C. helped to optimize the Spitzer observations. B.-O.D., J.G.I. and J.d.W. performed independent analyses of the Spitzer data. M.G., E.J., L.D., Ar.B., P.M., K.B., Y.A. and Z.B. performed the TRAPPIST observations and their analysis. S.M.L. obtained the director’s discretionary time on UKIRT, and, with E.J., managed the preparation of the UKIRT observations. M.T., J.L., F.S., E.B. and S.N.R. carried out atmospheric modelling for the planets and worked on the theoretical interpretation of their properties. V.V.G. managed the SAAO observations performed by C.S.F., M.R.B., D.L.H., A.C. and E.J.K. All co-authors assisted with writing the manuscript. A.H.M.J.T. prepared most of the figures.

Corresponding author

Correspondence to Michaël Gillon.

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Competing interests

The authors declare no competing financial interests.

Additional information

Reviewer Information Nature thanks D. Deming and I. Snellen for their contribution to the peer review of this work.

Extended data figures and tables

Extended Data Figure 1 Light curve of a triple transit of planets c, e and f.

The black points show the differential photometric measurements extracted from VLT/HAWK-I images taken on 11 December 2015, with the formal 1σ errors shown as vertical lines. The best-fit triple-transit model is shown as a red line. Possible configurations of the planets relative to the stellar disc are shown below the light curve for three different times (red, planet c; yellow, planet e; green, planet f). The relative positions and sizes of the planets, as well as the impact parameters, correspond to the values in Table 1.

Source data

Extended Data Figure 2 Transit light curve for planets d and e.

The black points show the photometric measurements, binned per 0.005 days (7.2 min). The error for each bin (shown as a vertical line) was computed as the 1σ error on the average. These light curves are divided by their best-fit instrumental models and by the best-fit transit models of other planets (for multiple transits). The best-fit transit models are shown as solid lines. The light curves are period-folded on the best-fit transit ephemeris given in Table 1, their relative shifts on the x-axis reflecting TTVs due to planet–planet interactions (see text). The epoch of the transit and the facility used to observe it are indicated above each light curve.

Source data

Extended Data Figure 4 TTVs measured for planets b, c, d, e, f and g.

For each planet, the best-fit TTV model computed with the n-body numerical integration code Mercury52 is shown as a red line. The 1 σ errors of the transit timing measurements are shown as vertical lines.

Source data

Extended Data Table 1 Summary of the observation set used

Full size table

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Source data

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Cite this article

Gillon, M., Triaud, A., Demory, BO. et al. Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1. Nature 542, 456–460 (2017). https://doi.org/10.1038/nature21360

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  • Received: 21 November 2016

  • Accepted: 21 December 2016

  • Published: 23 February 2017

  • Issue Date: 23 February 2017

  • DOI: https://doi.org/10.1038/nature21360