Possible evidence for a pair-instability supernova nature of ultra-early JWST sources

Recent JWST observations have revealed a population of unexpectedly bright sources at ultra-high redshift ( z > 15 ), challenging current models of early galaxy formation. One extreme example is , an F356W-dropout identified in the CEERS survey and initially interpreted as a luminous galaxy at z ∼ 30 , but subsequently found to be variable over an ∼ 800 day baseline. Motivated by this variability, we explore the alternative hypothesis that is a pair-instability supernova (PISN) originating from a massive ( ∼ 250 – 260 M ⊙ ), metal-free star. Using state-of-the-art PISN light curves, spectral energy distributions, and synthetic spectra, we show that a PISN at z ≃ 15 can plausibly reproduce the observed brightness, temporal evolution, photometry, and NIRSpec spectrum. We compare this scenario with alternative interpretations, including a local Y0 brown dwarf, and discuss observational tests to discriminate among them. If confirmed, this event would provide a rare window onto Population~III stars, and highlights the importance of transient contamination in ultra-high redshift galaxy samples.