Large Interferometer For Exoplanets (LIFE)

Astronomy and Astrophysics, vol. 664, pp. A21

Abstract

Context. One of the long-term goals of exoplanet science is the atmospheric characterization of dozens of small exoplanets in order to understand their diversity and search for habitable worlds and potential biosignatures. Achieving this goal requires a space mission of sufficient scale that can spatially separate the signals from exoplanets and their host stars and thus directly scrutinize the exoplanets and their atmospheres. Aims. We seek to quantify the exoplanet detection performance of a space-based mid-infrared (MIR) nulling interferometer that measures the thermal emission of exoplanets. We study the impact of various parameters and compare the performance with that of large single-aperture mission concepts that detect exoplanets in reflected light. Methods. We have developed an instrument simulator that considers all major astrophysical noise sources and coupled it with Monte Carlo simulations of a synthetic exoplanet population around main-sequence stars within 20 pc of the Sun. This allows us to quantify the number (and types) of exoplanets that our mission concept could detect. Considering single visits only, we discuss two different scenarios for distributing 2.5 yr of an initial search phase among the stellar targets. Different apertures sizes and wavelength ranges are investigated. Results. An interferometer consisting of four 2 m apertures working in the 4–18.5 μ.m wavelength range with a total instrument throughput of 5% could detect up to ≈550 exoplanets with radii between 0.5 and 6 R ⊕ with an integrated S / N ≥ 7. At least ≈160 of the detected exoplanets have radii ≤1.5 R ⊕ . Depending on the observing scenario, ≈25–45 rocky exoplanets (objects with radii between 0.5 and 1.5 R ⊕ ) orbiting within the empirical habitable zone (eHZ) of their host stars are among the detections. With four 3.5 m apertures, the total number of detections can increase to up to ≈770, including ≈60–80 rocky eHZ planets. With four times 1 m apertures, the maximum detection yield is ≈315 exoplanets, including ≤20 rocky eHZ planets. The vast majority of small, temperate exoplanets are detected around M dwarfs. The impact of changing the wavelength range to 3–20 μm or 6–17 μm on the detection yield is negligible. Conclusions. A large space-based MIR nulling interferometer will be able to directly detect hundreds of small, nearby exoplanets, tens of which would be habitable world candidates. This shows that such a mission can compete with large single-aperture reflected light missions. Further increasing the number of habitable world candidates, in particular around solar-type stars, appears possible via the implementation of a multi-visit strategy during the search phase. The high median S/N of most of the detected planets will allow for first estimates of their radii and effective temperatures and will help prioritize the targets for a second mission phase to obtain high-S/N thermal emission spectra, leveraging the superior diagnostic power of the MIR regime compared to shorter wavelengths.

Authors 67

1. Sascha P. Quanz

   ETH Zurich · Institute for Particle Physics and Astrophysics

   Affiliation as printed

   ETH Zurich, Institute for Particle Physics & Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zurich, Switzerland

   National Center of Competence in Research PlanetS, Gesellschaftsstrasse 6, 3012 Bern, Switzerland

2. Maurice Ottiger

   ETH Zurich · Institute for Particle Physics and Astrophysics

   Affiliation as printed

   ETH Zurich, Institute for Particle Physics & Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zurich, Switzerland

3. E. Fontanet

   ETH Zurich · Institute for Particle Physics and Astrophysics

   Affiliation as printed

   ETH Zurich, Institute for Particle Physics & Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zurich, Switzerland

4. Jens Kammerer

   Australian National University · Space Telescope Science Institute · European Southern Observatory

   Affiliation as printed

   European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany

   Research School of Astronomy & Astrophysics, Australian National University, ACT 2611, Australia

   Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 USA

5. Franziska Menti

   ETH Zurich · Institute for Particle Physics and Astrophysics

   Affiliation as printed

   ETH Zurich, Institute for Particle Physics & Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zurich, Switzerland

6. Felix Dannert

   ETH Zurich · Institute for Particle Physics and Astrophysics

   Affiliation as printed

   ETH Zurich, Institute for Particle Physics & Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zurich, Switzerland

7. Olivier Absil

   University of Liège

   Affiliation as printed

   STAR Institute, University of Liège, 19C allée du Six Aout, 4000 Liège, Belgium

8. Vladimir Airapetian

   Goddard Space Flight Center

   Affiliation as printed

   NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD, 20771 USA

9. Eleonora Alei

   ETH Zurich · Institute for Particle Physics and Astrophysics

   Affiliation as printed

   ETH Zurich, Institute for Particle Physics & Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zurich, Switzerland

   National Center of Competence in Research PlanetS, Gesellschaftsstrasse 6, 3012 Bern, Switzerland

10. Romain Allart

    Université de Montréal

    Affiliation as printed

    Department of Physics, and Institute for Research on Exoplanets, Université de Montréal, Montréal H3T 1J4, Canada

11. Daniel Angerhausen

    ETH Zurich · Institute for Particle Physics and Astrophysics

    Affiliation as printed

    ETH Zurich, Institute for Particle Physics & Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zurich, Switzerland

    National Center of Competence in Research PlanetS, Gesellschaftsstrasse 6, 3012 Bern, Switzerland

12. Sarah D. Blumenthal

    University of Oxford

    Affiliation as printed

    University of Oxford, Department of Atmospheric, Oceanic and Planetary Physics, Clarendon Laboratory, Sherrington Road, Oxford OX1 3PU, UK

13. Lars A. Buchhave

    DTU Space · Technical University of Denmark

    Affiliation as printed

    DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 328, DK-2800 Kgs. Lyngby, Denmark

14. J. Cabrera

    Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

    Affiliation as printed

    Department of Extrasolar Planets and Atmospheres, Institute for Planetary Research, German Aerospace Centre, Rutherfordstr. 2, 12489 Berlin, Germany

15. Óscar Carrión-González

    Technische Universität Berlin

    Affiliation as printed

    Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany

16. G. Chauvin

    Centre National de la Recherche Scientifique · Institut de Planétologie et d'Astrophysique de Grenoble · Université Grenoble Alpes

    Affiliation as printed

    Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France

17. W.C. Danchi

    Goddard Space Flight Center

    Affiliation as printed

    NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD, 20771 USA

18. Colin Dandumont

    University of Liège

    Affiliation as printed

    Centre Spatial de Liège, Université de Liège, Avenue Pré-Aily, 4031 Angleur, Belgium

19. Denis Defrère

    KU Leuven

    Affiliation as printed

    Institute of Astronomy, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium

20. Caroline Dorn

    University of Zurich

    Affiliation as printed

    University of Zurich, Institute of Computational Sciences, Winterthurerstrasse 190, 8057 Zurich, Switzerland

21. David Ehrenreich

    University of Geneva

    Affiliation as printed

    Observatoire astronomique de l’Université de Genève, chemin Pegasi 51b, 1290 Versoix, Switzerland

    Observatoire astronomique de l'Université de Genève, chemin Pegasi 51b, 1290 Versoix, Switzerland

22. Steve Ertel

    University of Arizona

    Affiliation as printed

    Large Binocular Telescope Observatory, 933 North Cherry Avenue, Tucson, AZ 85721 USA

    Steward Observatory, Department of Astronomy, University of Arizona, 993 N. Cherry Ave, Tucson, AZ, 85721 USA

23. Malcolm C. Fridlund Aachen Leiden Observatory

    Leiden University · Leiden Observatory · Chalmers University of Technology

    Affiliation as printed

    Department of Space, Earth & Environment, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden

    Leiden Observatory, Leiden University, 2333CA Leiden, The Netherlands

24. A. García Muñoz

    Technische Universität Berlin

    Affiliation as printed

    Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany

25. Carlos Gascón

    Institute of Space Sciences

    Affiliation as printed

    Institut de Ciències de l’Espai (ICE, CSIC), Campus UAB, C/Can Magrans s/n, 08193 Bellaterra, Spain

    Institut de Ciències de l'Espai (ICE, CSIC), Campus UAB, C/Can Magrans s/n, 08193 Bellaterra, Spain

26. Julien H. Girard

    Space Telescope Science Institute

    Affiliation as printed

    Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 USA

27. Adrian Michael Glauser

    ETH Zurich · Institute for Particle Physics and Astrophysics

    Affiliation as printed

    ETH Zurich, Institute for Particle Physics & Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zurich, Switzerland

28. John Lee Grenfell

    Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

    Affiliation as printed

    Department of Extrasolar Planets and Atmospheres, Institute for Planetary Research, German Aerospace Centre, Rutherfordstr. 2, 12489 Berlin, Germany

29. Greta Guidi

    ETH Zurich · Institute for Particle Physics and Astrophysics

    Affiliation as printed

    ETH Zurich, Institute for Particle Physics & Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zurich, Switzerland

    National Center of Competence in Research PlanetS, Gesellschaftsstrasse 6, 3012 Bern, Switzerland

30. J. Hagelberg

    University of Geneva

    Affiliation as printed

    Observatoire astronomique de l’Université de Genève, chemin Pegasi 51b, 1290 Versoix, Switzerland

    Observatoire astronomique de l'Université de Genève, chemin Pegasi 51b, 1290 Versoix, Switzerland

31. Ravit Helled

    University of Zurich

    Affiliation as printed

    University of Zurich, Institute of Computational Sciences, Winterthurerstrasse 190, 8057 Zurich, Switzerland

32. Michael Ireland

    Australian National University

    Affiliation as printed

    Research School of Astronomy & Astrophysics, Australian National University, ACT 2611, Australia

33. M. Janson

    Stockholm University · AlbaNova

    Affiliation as printed

    Department of Astronomy, Stockholm University, Alba Nova University Center, 10691 Stockholm, Sweden

34. Ravi Kopparapu

    Goddard Space Flight Center

    Affiliation as printed

    NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD, 20771 USA

35. J. Korth

    Chalmers University of Technology

    Affiliation as printed

    Department of Space, Earth and Environment, Astronomy and Plasma Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden

36. Thea Kozakis

    DTU Space · Technical University of Denmark

    Affiliation as printed

    DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 328, DK-2800 Kgs. Lyngby, Denmark

37. Stefan Kraus

    University of Exeter

    Affiliation as printed

    University of Exeter, School of Physics and Astronomy, Stocker Road, Exeter EX4 4QL, UK

38. Alain M. Leger

    Université Paris-Sud · Centre National de la Recherche Scientifique · Institut d'Astrophysique Spatiale

    Affiliation as printed

    IAS, CNRS (UMR 8617), bât 121, Univ. Paris-Sud, 91405 Orsay, France

39. L. Leedjärv

    Tartu Observatory · University of Tartu

    Affiliation as printed

    University of Tartu, Tartu Observatory, 1 Observatooriumi Str., 61602 Tõravere, Tartumaa, Estonia

40. Tim Lichtenberg

    University of Oxford

    Affiliation as printed

    University of Oxford, Department of Atmospheric, Oceanic and Planetary Physics, Clarendon Laboratory, Sherrington Road, Oxford OX1 3PU, UK

41. J. Lillo-Box

    Centro de Astrobiología

    Affiliation as printed

    Centro de Astrobiología (CAB, CSIC-INTA), Depto. de Astrofísica, ESAC campus 28692 Villanueva de la Cañada (Madrid), Spain

42. Hendrik Linz

    Max Planck Institute for Astronomy

    Affiliation as printed

    Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany

43. R. Liseau

    Chalmers University of Technology

    Affiliation as printed

    Department of Space, Earth & Environment, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden

44. Jérôme Loïcq

    University of Liège

    Affiliation as printed

    Centre Spatial de Liège, Université de Liège, Avenue Pré-Aily, 4031 Angleur, Belgium

45. F. Malbet

    Centre National de la Recherche Scientifique · Institut de Planétologie et d'Astrophysique de Grenoble · Université Grenoble Alpes

    Affiliation as printed

    Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France

46. Joice Mathew

    Australian National University

    Affiliation as printed

    Research School of Astronomy & Astrophysics, Australian National University, ACT 2611, Australia

47. Bertrand P. Mennesson

    California Institute of Technology · Jet Propulsion Laboratory

    Affiliation as printed

    Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 USA

48. M. R. Meyer

    University of Michigan

    Affiliation as printed

    Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 USA

49. Lokesh Mishra

    University of Geneva · University of Bern

    Affiliation as printed

    National Center of Competence in Research PlanetS, Gesellschaftsstrasse 6, 3012 Bern, Switzerland

    Observatoire astronomique de l’Université de Genève, chemin Pegasi 51b, 1290 Versoix, Switzerland

    Physikalisches Institut, Universität Bern, Gesellschaftsstrasse 6, 3012 Bern, Switzerland

    Observatoire astronomique de l'Université de Genève, chemin Pegasi 51b, 1290 Versoix, Switzerland

50. Karan Molaverdikhani

    Heidelberg University · Max Planck Institute for Astronomy

    Affiliation as printed

    Landessternwarte, Zentrum für Astronomie der Universität Heidelberg, Königstuhl 12, 69117 Heidelberg, Germany

    Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany

51. Lena Noack

    Freie Universität Berlin

    Affiliation as printed

    Freie Universitat Berlin, Department of Earth Sciences, Malteserstr. 74–100, 12249 Berlin, Germany

52. A. Oza

    University of Bern · California Institute of Technology · Jet Propulsion Laboratory

    Affiliation as printed

    Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 USA

    Physikalisches Institut, Universität Bern, Gesellschaftsstrasse 6, 3012 Bern, Switzerland

53. Ε. Πάλλη

    Universidad de La Laguna · Instituto de Astrofísica de Canarias

    Affiliation as printed

    Dept. Astrofísica, Universidad de La Laguna (ULL), 38206 La Laguna, Tenerife, Spain

    Instituto de Astrofísica de Canarias (IAC), 38200 La Laguna, Tenerife, Spain

54. H. Parviainen

    Universidad de La Laguna · Instituto de Astrofísica de Canarias

    Affiliation as printed

    Dept. Astrofísica, Universidad de La Laguna (ULL), 38206 La Laguna, Tenerife, Spain

    Instituto de Astrofísica de Canarias (IAC), 38200 La Laguna, Tenerife, Spain

55. Andreas Quirrenbach

    Heidelberg University

    Affiliation as printed

    Landessternwarte, Zentrum für Astronomie der Universität Heidelberg, Königstuhl 12, 69117 Heidelberg, Germany

56. Heike Rauer

    Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

    Affiliation as printed

    Department of Extrasolar Planets and Atmospheres, Institute for Planetary Research, German Aerospace Centre, Rutherfordstr. 2, 12489 Berlin, Germany

57. I. Ribas

    Institute of Space Sciences · Institut d'Estudis Espacials de Catalunya

    Affiliation as printed

    Institut de Ciències de l’Espai (ICE, CSIC), Campus UAB, C/Can Magrans s/n, 08193 Bellaterra, Spain

    Institut d’Estudis Espacials de Catalunya (IEEC), C/Gran Capitá 2–4, 08034 Barcelona, Spain

    Institut d'Estudis Espacials de Catalunya (IEEC), C/Gran Capitá 2–4, 08034 Barcelona, Spain

    Institut de Ciències de l'Espai (ICE, CSIC), Campus UAB, C/Can Magrans s/n, 08193 Bellaterra, Spain

58. Malena Rice

    Yale University

    Affiliation as printed

    Department of Astronomy, Yale University, New Haven, CT 06511 USA

59. A Romagnolo

    Nicolaus Copernicus Astronomical Center · Polish Academy of Sciences

    Affiliation as printed

    Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, 00–716 Warsaw, Poland

60. Sarah Rugheimer

    University of Oxford

    Affiliation as printed

    University of Oxford, Department of Atmospheric, Oceanic and Planetary Physics, Clarendon Laboratory, Sherrington Road, Oxford OX1 3PU, UK

61. Edward W. Schwieterman

    University of California, Riverside

    Affiliation as printed

    Department of Earth and Planetary Sciences, University of California, Riverside, 900 University Ave. Riverside, CA 92521 USA

62. Eugene Serabyn

    California Institute of Technology · Jet Propulsion Laboratory

    Affiliation as printed

    Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 USA

63. Keivan Guadalupe Stassun

    Vanderbilt University

    Affiliation as printed

    Vanderbilt University, Department of Physics & Astronomy, 6301 Stevenson Center Ln., Nashville, TN 37235 USA

64. J. Szulágyi

    ETH Zurich · Institute for Particle Physics and Astrophysics

    Affiliation as printed

    ETH Zurich, Institute for Particle Physics & Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zurich, Switzerland

65. Haiyang S. Wang

    ETH Zurich · Institute for Particle Physics and Astrophysics

    Affiliation as printed

    ETH Zurich, Institute for Particle Physics & Astrophysics, Wolfgang-Pauli-Str. 27, 8093 Zurich, Switzerland

    National Center of Competence in Research PlanetS, Gesellschaftsstrasse 6, 3012 Bern, Switzerland

66. Fabian Wunderlich

    Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

    Affiliation as printed

    Department of Extrasolar Planets and Atmospheres, Institute for Planetary Research, German Aerospace Centre, Rutherfordstr. 2, 12489 Berlin, Germany

67. Mark C. Wyatt

    University of Cambridge

    Affiliation as printed

    Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK