A Preliminary Search for Planets and Exozodiacal Emission Around $\alpha$ Centauri A with JWST/MIRI}

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 February 2025, were compromised by having only one successful roll and degraded performance due to the misalignment of α Cen A and the best-matching reference observation behind the MIRI coronagraph (∆r ∼ 10 mas). We set preliminary upper limits on both the presence of a planet and an exozodiacal dust disk. The observations are sensitive to a planet warmed by α Cen A 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).