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Published April 10, 2025 | Version Published
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The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. III. Aperture Masking Interferometric Observations of the Star HIP 65426 at 3.8 μm

Creators

  • 1. ROR icon University of Queensland
  • 2. ROR icon University of Exeter
  • 3. ROR icon University of California, Irvine
  • 4. ROR icon Space Telescope Science Institute
  • 5. ROR icon Infrared Processing and Analysis Center
  • 6. ROR icon Leiden University
  • 7. ROR icon Cerro Tololo Inter-American Observatory
  • 8. ROR icon University of Michigan–Ann Arbor
  • 9. ROR icon The University of Texas at Austin
  • 10. ROR icon United States Naval Research Laboratory
  • 11. ROR icon University of California, Santa Cruz
  • 12. ROR icon University of Edinburgh
  • 13. ROR icon American Museum of Natural History
  • 14. ROR icon University of Arizona
  • 15. ROR icon University of Liège
  • 16. ROR icon Johns Hopkins University
  • 17. ROR icon Laboratory of Space Studies and Instrumentation in Astrophysics
  • 18. ROR icon The Open University
  • 19. ROR icon Grenoble Alpes University
  • 20. ROR icon Friedrich Schiller University Jena
  • 21. ROR icon Goddard Space Flight Center
  • 22. ROR icon University of California, Berkeley
  • 23. Aix Marseille Univ, CNRS, CNES, LAM, 13013 Marseille, France
  • 24. ROR icon Lagrange Laboratory
  • 25. ROR icon The University of Texas at San Antonio
  • 26. ROR icon University of Hawaii at Hilo
  • 27. ROR icon Instituto de Astrofísica de Andalucía
  • 28. ROR icon University of California, Los Angeles
  • 29. ROR icon Eureka Scientific
  • 30. ROR icon Cornell University
  • 31. ROR icon Max Planck Institute for Astronomy
  • 32. ROR icon University of California, San Diego
  • 33. ROR icon Stockholm University
  • 34. ROR icon Search for Extraterrestrial Intelligence
  • 35. ROR icon University of Warwick
  • 36. ROR icon Astrobiology Center
  • 37. ROR icon University of Paris
  • 38. ROR icon Bay Area Environmental Research Institute
  • 39. ROR icon University of Hawaii at Manoa
  • 40. ROR icon California Institute of Technology
  • 41. ROR icon Kavli Institute for Particle Astrophysics and Cosmology
  • 42. ROR icon University of Cambridge
  • 43. ROR icon National Research Council Canada
  • 44. ROR icon University of Geneva
  • 45. ROR icon Western University
  • 46. ROR icon University of California, Santa Barbara
  • 47. ROR icon Institut de Recherche sur les Lois Fondamentales de l'Univers
  • 48. ROR icon ETH Zurich
  • 49. ROR icon University of Valparaíso
  • 50. ROR icon Heidelberg University
  • 51. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 52. ROR icon Jet Propulsion Lab
  • 53. ROR icon University of Tokyo
  • 54. ROR icon Shanghai Jiao Tong University
  • 55. ROR icon Trinity College Dublin
  • 56. ROR icon Northwestern University
  • 57. ROR icon Smith College
  • 58. ROR icon Diego Portales University
  • 59. Millennium Nucleus on Young Exoplanets and their Moons (YEMS).
  • 60. ROR icon Ludwig-Maximilians-Universität München
  • 61. ROR icon University of Bern

Abstract

We present aperture masking interferometry (AMI) observations of the star HIP 65426 at 3.8 μm, as part of the JWST Direct Imaging Early Release Science program, obtained using the Near Infrared Imager and Slitless Spectrograph instrument. This mode provides access to very small inner working angles (even separations slightly below the Michelson limit of 0.5λ/D for an interferometer), which are inaccessible with the classical inner working angles of the JWST coronagraphs. When combined with JWST's unprecedented infrared sensitivity, this mode has the potential to probe a new portion of parameter space across a wide array of astronomical observations. Using this mode, we are able to achieve a 5σ contrast of ΔmF380M ∼ 7.62 ± 0.13 mag relative to the host star at separations ≳0.″07, and the contrast deteriorates steeply at separations ≲0.″07. However, we detect no additional companions interior to the known companion HIP 65426b (at separation ∼0.″82 or 87_(−31)^(+108)au). Our observations thus rule out companions more massive than 10–12 MJup at separations ∼10–20 au from HIP 65426, a region out of reach of ground- or space-based coronagraphic imaging. These observations confirm that the AMI mode on JWST is sensitive to planetary mass companions at close-in separations (≳0.″07), even for thousands of more distant stars at ∼100 pc, in addition to the stars in the nearby young moving groups and associations, as stated in previous works. This result will allow the planning and successful execution of future observations to probe the inner regions of nearby stellar systems, opening an essentially unexplored parameter space.

Copyright and License

© 2025. The Author(s). Published by the American Astronomical Society.

Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

Acknowledgement

This work is based on observations made with the NASA/ESA/CSA JWST and obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute. The specific observations analyzed can be accessed via 10.17909/8by2-x206. We are truly grateful for the countless hours that thousands of people have devoted to the design, construction, and commissioning of JWST. We thank the anonymous referee for comments that have been crucial toward the improvement of this Letter. This project was supported by a grant from STScI (JWST-ERS-01386) under NASA contract NAS5-03127. S.R. was supported by the Global Excellence Award at the University of Exeter. This work is based in part on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia e Inovações (MCTI/LNA) of Brasil, the US National Science Foundation's NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). This work has also made use of the SPHERE Data Centre, jointly operated by OSUG/IPAG (Grenoble), PYTHEAS/LAM/CeSAM (Marseille), OCA/Lagrange (Nice), Observatoire de Paris/LESIA (Paris), and Observatoire de Lyon/CRAL, as well as being supported by a grant from Labex OSUG@2020 (Investissements d'avenir—ANR10 LABX56). This work has benefited from the 2022 Exoplanet Summer Program in the Other Worlds Laboratory (OWL) at the University of California, Santa Cruz, a program funded by the Heising–Simons Foundation.

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Additional details

Related works

Is new version of
Discussion Paper: arXiv:2310.11508 (arXiv)
Is supplemented by
Dataset: 10.17909/8by2-x206 (DOI)

Funding

Space Telescope Science Institute
JWST-ERS-01386
National Aeronautics and Space Administration
NAS5-03127
University of Exeter
Global Excellence Award -
Agence Nationale de la Recherche
ANR10 LABX56
Heising-Simons Foundation

Dates

Accepted
2025-01-19
Available
2025-04-09
Published

Caltech Custom Metadata

Caltech groups
Astronomy Department, Infrared Processing and Analysis Center (IPAC), Division of Physics, Mathematics and Astronomy (PMA)
Publication Status
Published