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

Authors

• Shrishmoy Ray, The University of Queensland
• Steph Sallum, University of California, Irvine
• Sasha Hinkley, University of Exeter
• Anand Sivaramkrishnan, Space Telescope Science Institute
• Rachel Cooper, Space Telescope Science Institute
• Jens Kammerer, Space Telescope Science Institute
• Alexandra Z. Greebaum, Infrared Processing & Analysis Center
• Deeparshi Thatte, Space Telescope Science Institute
• Tomas Stolker, Sterrewacht Leiden
• Cecilia Lazzoni, University of Exeter
• Andrei Tokovinin, Cerro Tololo Inter American Observatory
• Matthew de Furio, University of Michigan, Ann Arbor
• Samuel Factor, College of Natural Sciences
• Michael Meyer, University of Michigan, Ann Arbor
• Jordan M. Stone, U.S. Naval Research Laboratory
• Aarynn Carter, University of California, Santa Cruz
• Beth Biller, University of Edinburgh, Institute for Astronomy
• Andrew Skemer, University of California, Santa Cruz
• Genaro Suárez, American Museum of Natural History
• Jarron M. Leisenring, The University of Arizona
• Marshall D. Perrin, Space Telescope Science Institute
• Adam L. Kraus, College of Natural Sciences
• Olivier Absil, Université de Liège
• William O. Balmer, Space Telescope Science Institute
• Anthony Boccaletti, L'Observatoire de Paris
• Mariangela Bonavita, The Open University
• Mickael Bonnefoy, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
• Mark Booth, Friedrich-Schiller-Universität Jena
• Brendan P. Bowler, College of Natural Sciences
• Zackery W. Briesemeister, NASA Goddard Space Flight Center
• Marta L. Bryan, University of California, Berkeley
• Per Calissendorff, University of Michigan, Ann Arbor

Author ORCID Identifier

Kimberly Ward-Duong: 0000-0002-4479-8291

Document Type

Article

Publication Date

4-10-2025

Publication Title

Astrophysical Journal Letters

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 8 7 − 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.

Volume

983

Issue

1

DOI

https://doi.org/10.3847/2041-8213/adaeb7

ISSN

20418205

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Rights

© 2025 The Authors

Version

Version of Record

Recommended Citation

Ray, Shrishmoy; Sallum, Steph; Hinkley, Sasha; Sivaramkrishnan, Anand; Cooper, Rachel; Kammerer, Jens; Greebaum, Alexandra Z.; Thatte, Deeparshi; Stolker, Tomas; Lazzoni, Cecilia; Tokovinin, Andrei; Furio, Matthew de; Factor, Samuel; Meyer, Michael; Stone, Jordan M.; Carter, Aarynn; Biller, Beth; Skemer, Andrew; Suárez, Genaro; Leisenring, Jarron M.; Perrin, Marshall D.; Kraus, Adam L.; Absil, Olivier; Balmer, William O.; Boccaletti, Anthony; Bonavita, Mariangela; Bonnefoy, Mickael; Booth, Mark; Bowler, Brendan P.; Briesemeister, Zackery W.; Bryan, Marta L.; and Calissendorff, Per, "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" (2025). Astronomy: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/ast_facpubs/138