Alpha Centauri

A Preliminary Search For Planets and Exozodiacal Emission Around Alpha Centauri A with JWST/MIRI

By Keith Cowing

Press Release

Research Notes of the AAS,

May 26, 2025

Filed under Alpha Centauri A, coronagraph, exoplanet, exozodiacal dust, imaging, JWST, MIRI, Research Notes of the AAS, telescope

A Preliminary Search For Planets and Exozodiacal Emission Around Alpha Centauri A with JWST/MIRI — F1550C image of α Cen AB. α Cen B is saturated near the top and α Cen A is behind the F1550C mask near the center. Two known background stars are labeled (KS2 inset, detected after PSF subtraction; and KS5). The (right) colorbar (for the Stage 2b image) is logarithmically scaled in MJy/sr. A ≈ 35 radius region around α Cen A is expanded. (a) The original α Cen AB PSF-subtracted image. Dashed lines indicate the FQPM boundaries. A likely artifact is boxed. (b) An identical reduction after injecting STPSF planet models (circled). (c) An identical reduction after injecting an exozodiacal disk model (boxed). The (bottom) colorbar (for the reduced images and KS2) is linearly scaled in MJy/sr. — Research Notes of the AAS

We present F1550C (15.5 μm) coronagraphic imaging observations of the nearest solar-type star α Cen A using the James Webb Space Telescope (JWST) Mid-InfraRed Instrument (MIRI).

The observations, executed in 2025 February, were compromised by having only one successful roll and degraded performance due to a position mismatch (Δr ∼ 10 mas) between α Cen A and the best-matching reference observation behind the MIRI coronagraph.

We set preliminary upper limits on both the presence of a planet and an exozodiacal dust disk. The observations are sensitive to a planet heated by α Cen A (200–250 K) with a radius ≳1 RJup at a separation of 1 5 (2 au) and zodiacal dust emission at the level of ≳5–10 times the brightness of our own zodiacal cloud.

A complete analysis of all JWST/MIRI observations of α Cen A is forthcoming in Paper I (Beichman & Sanghi et al. 2025, in preparation) and Paper II (Sanghi & Beichman et al. 2025, in preparation).

A Preliminary Search for Planets and Exozodiacal Emission Around α Centauri A with JWST/MIRI, Research Notes of the AAS, (open access)

Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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