Worlds Next Door: A Candidate Giant Planet Imaged in the Habitable Zone of α Centauri A. II. Binary Star Modeling, Planet and Exozodi Search, and Sensitivity Analysis
The James Webb Space Telescope (JWST) observed our closest solar twin, α Centauri A ( α Cen A), with the Mid-Infrared Instrument in the F1550C (15.5 μ m) coronagraphic imaging mode at three distinct epochs between 2024 August and 2025 April. For the first time with JWST, we demonstrate the applicati...
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/2041-8213/adf53e |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849393502418370560 |
|---|---|
| author | Aniket Sanghi Charles Beichman Dimitri Mawet William O. Balmer Nicolas Godoy Laurent Pueyo Anthony Boccaletti Max Sommer Alexis Bidot Elodie Choquet Pierre Kervella Pierre-Olivier Lagage Jarron Leisenring Jorge Llop-Sayson Michael Ressler Kevin Wagner Mark Wyatt |
| author_facet | Aniket Sanghi Charles Beichman Dimitri Mawet William O. Balmer Nicolas Godoy Laurent Pueyo Anthony Boccaletti Max Sommer Alexis Bidot Elodie Choquet Pierre Kervella Pierre-Olivier Lagage Jarron Leisenring Jorge Llop-Sayson Michael Ressler Kevin Wagner Mark Wyatt |
| author_sort | Aniket Sanghi |
| collection | DOAJ |
| description | The James Webb Space Telescope (JWST) observed our closest solar twin, α Centauri A ( α Cen A), with the Mid-Infrared Instrument in the F1550C (15.5 μ m) coronagraphic imaging mode at three distinct epochs between 2024 August and 2025 April. For the first time with JWST, we demonstrate the application of reference star differential imaging to simultaneously subtract the coronagraphic image of a primary star ( α Cen A) and the point-spread function (PSF) of its binary companion ( α Cen B) to conduct a deep search for exoplanets and exozodiacal dust emission. We achieve a typical 5 σ point-source contrast sensitivity between ∼10 ^−5 and 10 ^−4 at separations ≳ 1″ and an exozodiacal disk (coplanar with α Cen AB) sensitivity of ∼5–8× the solar system’s zodiacal cloud around α Cen A. The latter is an extraordinary limit, representing the deepest sensitivity to exozodiacal disks achieved for any stellar system to date. Additionally, postprocessing with the principal-component-analysis-based Karhunen–Loéve image processing algorithm reveals a point source, called S 1, in 2024 August, detected at signal-to-noise ratio of 4–6 (3.3–4.3 σ ), a projected separation of ≈1 $\mathop{.}\limits^{^{\prime\prime} }$ 5 (2 au), and with an F1550C flux density (contrast) of ≈3.5 mJy (≈5.5 × 10 ^−5 ). Various tests conducted with the available data show that S 1 is unlikely to be a detector artifact or PSF-subtraction artifact and confirm that it is neither a background nor a foreground object. S 1 is not redetected in two follow-up observations (2025 February and April). If S 1 is astrophysical in nature, the only explanation is that it has moved to a region of poor sensitivity due to orbital motion. We perform PSF injection–recovery tests and provide 2D sensitivity maps for each epoch to enable orbital completeness calculations. Additional observations, with JWST or upcoming facilities, are necessary to redetect candidate S 1 and confirm its nature as a planet orbiting our nearest solar-type neighbor, α Cen A. More broadly, this program highlights the complexity of analyzing a dynamic binary astrophysical scene and the challenges associated with confirming short-period (∼few years) planet candidates identified without prior orbital constraints in direct imaging searches. This Letter is second in a series of two papers: Paper I discusses the observation strategy and presents the astrophysical case (physical and orbital properties) for S 1 as a planet candidate. |
| format | Article |
| id | doaj-art-0bb2e4b966fb4843afcbeebd135f2553 |
| institution | Kabale University |
| issn | 2041-8205 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Letters |
| spelling | doaj-art-0bb2e4b966fb4843afcbeebd135f25532025-08-20T03:40:24ZengIOP PublishingThe Astrophysical Journal Letters2041-82052025-01-019892L2310.3847/2041-8213/adf53eWorlds Next Door: A Candidate Giant Planet Imaged in the Habitable Zone of α Centauri A. II. Binary Star Modeling, Planet and Exozodi Search, and Sensitivity AnalysisAniket Sanghi0https://orcid.org/0000-0002-1838-4757Charles Beichman1https://orcid.org/0000-0002-5627-5471Dimitri Mawet2https://orcid.org/0000-0002-8895-4735William O. Balmer3https://orcid.org/0000-0001-6396-8439Nicolas Godoy4https://orcid.org/0000-0003-0958-2150Laurent Pueyo5https://orcid.org/0000-0003-3818-408XAnthony Boccaletti6https://orcid.org/0000-0001-9353-2724Max Sommer7https://orcid.org/0000-0003-4761-5785Alexis Bidot8https://orcid.org/0000-0002-9799-2303Elodie Choquet9https://orcid.org/0000-0002-9173-0740Pierre Kervella10https://orcid.org/0000-0003-0626-1749Pierre-Olivier Lagage11Jarron Leisenring12https://orcid.org/0000-0002-0834-6140Jorge Llop-Sayson13https://orcid.org/0000-0002-3414-784XMichael Ressler14https://orcid.org/0000-0001-5644-8830Kevin Wagner15https://orcid.org/0000-0002-4309-6343Mark Wyatt16https://orcid.org/0000-0001-9064-5598Cahill Center for Astronomy and Astrophysics, California Institute of Technology , 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125, USA ; asanghi@caltech.edu; NSF Graduate Research FellowNASA Exoplanet Science Institute , Caltech-IPAC, Pasadena, CA 91125, USA ; chas@ipac.caltech.edu; Jet Propulsion Laboratory, California Institute of Technology , Pasadena, CA 91109, USACahill Center for Astronomy and Astrophysics, California Institute of Technology , 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125, USA ; asanghi@caltech.edu; Jet Propulsion Laboratory, California Institute of Technology , Pasadena, CA 91109, USADepartment of Physics & Astronomy, Johns Hopkins University , 3400 North Charles Street, Baltimore, MD 21218, USA; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USAAix Marseille Univ ersité, CNRS, CNES, LAM, Marseille, FranceSpace Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USALIRA, Observatoire de Paris, Université PSL, Sorbonne Université , Université Paris Cité, CY Cergy Paris Université, CNRS, 5 Place Jules Janssen, 92195 Meudon, FranceInstitute of Astronomy, University of Cambridge , Madingley Road, Cambridge CB3 0HA, UKSpace Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USAAix Marseille Univ ersité, CNRS, CNES, LAM, Marseille, FranceLIRA, Observatoire de Paris, Université PSL, Sorbonne Université , Université Paris Cité, CY Cergy Paris Université, CNRS, 5 Place Jules Janssen, 92195 Meudon, France; French-Chilean Laboratory for Astronomy, IRL 3386, CNRS and Universidad de Chile , Casilla 36-D, Santiago, ChileUniversité Paris-Saclay, Université Paris Cité , CEA, CNRS, AIM, 91191 Gif-sur-Yvette, FranceSteward Observatory, University of Arizona , Tucson, AZ 85721, USAJet Propulsion Laboratory, California Institute of Technology , Pasadena, CA 91109, USAJet Propulsion Laboratory, California Institute of Technology , Pasadena, CA 91109, USASteward Observatory, University of Arizona , Tucson, AZ 85721, USAInstitute of Astronomy, University of Cambridge , Madingley Road, Cambridge CB3 0HA, UKThe James Webb Space Telescope (JWST) observed our closest solar twin, α Centauri A ( α Cen A), with the Mid-Infrared Instrument in the F1550C (15.5 μ m) coronagraphic imaging mode at three distinct epochs between 2024 August and 2025 April. For the first time with JWST, we demonstrate the application of reference star differential imaging to simultaneously subtract the coronagraphic image of a primary star ( α Cen A) and the point-spread function (PSF) of its binary companion ( α Cen B) to conduct a deep search for exoplanets and exozodiacal dust emission. We achieve a typical 5 σ point-source contrast sensitivity between ∼10 ^−5 and 10 ^−4 at separations ≳ 1″ and an exozodiacal disk (coplanar with α Cen AB) sensitivity of ∼5–8× the solar system’s zodiacal cloud around α Cen A. The latter is an extraordinary limit, representing the deepest sensitivity to exozodiacal disks achieved for any stellar system to date. Additionally, postprocessing with the principal-component-analysis-based Karhunen–Loéve image processing algorithm reveals a point source, called S 1, in 2024 August, detected at signal-to-noise ratio of 4–6 (3.3–4.3 σ ), a projected separation of ≈1 $\mathop{.}\limits^{^{\prime\prime} }$ 5 (2 au), and with an F1550C flux density (contrast) of ≈3.5 mJy (≈5.5 × 10 ^−5 ). Various tests conducted with the available data show that S 1 is unlikely to be a detector artifact or PSF-subtraction artifact and confirm that it is neither a background nor a foreground object. S 1 is not redetected in two follow-up observations (2025 February and April). If S 1 is astrophysical in nature, the only explanation is that it has moved to a region of poor sensitivity due to orbital motion. We perform PSF injection–recovery tests and provide 2D sensitivity maps for each epoch to enable orbital completeness calculations. Additional observations, with JWST or upcoming facilities, are necessary to redetect candidate S 1 and confirm its nature as a planet orbiting our nearest solar-type neighbor, α Cen A. More broadly, this program highlights the complexity of analyzing a dynamic binary astrophysical scene and the challenges associated with confirming short-period (∼few years) planet candidates identified without prior orbital constraints in direct imaging searches. This Letter is second in a series of two papers: Paper I discusses the observation strategy and presents the astrophysical case (physical and orbital properties) for S 1 as a planet candidate.https://doi.org/10.3847/2041-8213/adf53eJames Webb Space TelescopeCoronagraphic imagingExtrasolar gaseous giant planetsExozodiacal dust |
| spellingShingle | Aniket Sanghi Charles Beichman Dimitri Mawet William O. Balmer Nicolas Godoy Laurent Pueyo Anthony Boccaletti Max Sommer Alexis Bidot Elodie Choquet Pierre Kervella Pierre-Olivier Lagage Jarron Leisenring Jorge Llop-Sayson Michael Ressler Kevin Wagner Mark Wyatt Worlds Next Door: A Candidate Giant Planet Imaged in the Habitable Zone of α Centauri A. II. Binary Star Modeling, Planet and Exozodi Search, and Sensitivity Analysis The Astrophysical Journal Letters James Webb Space Telescope Coronagraphic imaging Extrasolar gaseous giant planets Exozodiacal dust |
| title | Worlds Next Door: A Candidate Giant Planet Imaged in the Habitable Zone of α Centauri A. II. Binary Star Modeling, Planet and Exozodi Search, and Sensitivity Analysis |
| title_full | Worlds Next Door: A Candidate Giant Planet Imaged in the Habitable Zone of α Centauri A. II. Binary Star Modeling, Planet and Exozodi Search, and Sensitivity Analysis |
| title_fullStr | Worlds Next Door: A Candidate Giant Planet Imaged in the Habitable Zone of α Centauri A. II. Binary Star Modeling, Planet and Exozodi Search, and Sensitivity Analysis |
| title_full_unstemmed | Worlds Next Door: A Candidate Giant Planet Imaged in the Habitable Zone of α Centauri A. II. Binary Star Modeling, Planet and Exozodi Search, and Sensitivity Analysis |
| title_short | Worlds Next Door: A Candidate Giant Planet Imaged in the Habitable Zone of α Centauri A. II. Binary Star Modeling, Planet and Exozodi Search, and Sensitivity Analysis |
| title_sort | worlds next door a candidate giant planet imaged in the habitable zone of α centauri a ii binary star modeling planet and exozodi search and sensitivity analysis |
| topic | James Webb Space Telescope Coronagraphic imaging Extrasolar gaseous giant planets Exozodiacal dust |
| url | https://doi.org/10.3847/2041-8213/adf53e |
| work_keys_str_mv | AT aniketsanghi worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT charlesbeichman worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT dimitrimawet worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT williamobalmer worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT nicolasgodoy worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT laurentpueyo worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT anthonyboccaletti worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT maxsommer worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT alexisbidot worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT elodiechoquet worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT pierrekervella worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT pierreolivierlagage worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT jarronleisenring worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT jorgellopsayson worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT michaelressler worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT kevinwagner worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis AT markwyatt worldsnextdooracandidategiantplanetimagedinthehabitablezoneofacentauriaiibinarystarmodelingplanetandexozodisearchandsensitivityanalysis |