The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems I: High-contrast Imaging of the Exoplanet HIP 65426 b from 2 to 16 μm
Abstract
We present JWST Early Release Science coronagraphic observations of the super-Jupiter exoplanet, HIP 65426b, with the Near-Infrared Camera (NIRCam) from 2 to 5 μm, and with the Mid-Infrared Instrument (MIRI) from 11 to 16 μm. At a separation of ∼0.ˮ82 (87⁺¹⁰⁸₋₃₁ au), HIP 65426b is clearly detected in all seven of our observational filters, representing the first images of an exoplanet to be obtained by JWST, and the first-ever direct detection of an exoplanet beyond 5 μm. These observations demonstrate that JWST is exceeding its nominal predicted performance by up to a factor of 10, depending on separation and subtraction method, with measured 5σ contrast limits of ∼1 × 10⁻⁵ and ∼2 × 10⁻⁴ at 1'' for NIRCam at 4.4 μm and MIRI at 11.3 μm, respectively. These contrast limits provide sensitivity to sub-Jupiter companions with masses as low as 0.3Mⱼᵤₚ beyond separations of ∼100 au. Together with existing ground-based near-infrared data, the JWST photometry are fit well by a BT-SETTL atmospheric model from 1 to 16 μm, and they span ∼97% of HIP 65426b's luminous range. Independent of the choice of model atmosphere, we measure an empirical bolometric luminosity that is tightly constrained between log(L₆ₒₗ/LꙨ) −4.31 and −4.14, which in turn provides a robust mass constraint of 7.1 ± 1.2 Mⱼᵤₚ. In totality, these observations confirm that JWST presents a powerful and exciting opportunity to characterize the population of exoplanets amenable to high-contrast imaging in greater detail. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000624250Publication status
publishedExternal links
Journal / series
The Astrophysical Journal LettersVolume
Pages / Article No.
Publisher
IOP PublishingSubject
Exoplanets; Exoplanet astronomy; Extrasolar gaseous planetsOrganisational unit
09680 - Quanz, Sascha Patrick / Quanz, Sascha Patrick
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Is new version of: https://doi.org/10.3929/ethz-b-000592856
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