JWST difference imaging from COSMOS-Web and PRIMER has yielded 68 high-redshift supernovae including a core-collapse event at z>3 and a Type Ia at z>2, demonstrating the feasibility of wide-area time-domain searches in the early universe.
Possible evidence for a pair-instability supernova nature of ultra-early JWST sources
5 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
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 'Capotauro', an F356W-dropout identified in the CEERS survey and initially interpreted as a luminous galaxy at $z\sim30$, but subsequently found to be variable over an $\sim 800$ day baseline. Motivated by this variability, we explore the alternative hypothesis that Capotauro is a pair-instability supernova (PISN) originating from a massive ($250-260\,M_\odot$), metal-free star. Using state-of-the-art PISN light curves, spectral energy distributions, and synthetic spectra, we show that a PISN at $z\simeq 15$ 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.
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2026 5representative citing papers
NEFERTITI simulations show that the Milky Way's most metal-poor stars largely come from a handful of accreted massive dwarf galaxies, while reproducing the JWST Hebe galaxy at z~11 as a pure Population III system.
High-redshift HeII emitter observations confirm a >50% PopIII stellar mass fraction and favor top-heavy IMFs for the first stars with total masses 2e4 to 6e5 solar masses.
Low-energy PISNe from 140 solar-mass Pop III stars produce second-generation stars at median [Fe/H] ~ -5.5 with odd-even patterns, but their absence from EMP observations disfavors PISNe as the main early enrichment channel.
Two high-redshift galaxy candidates are reidentified as ultra-cool Y-type brown dwarfs at ~500 pc based on NIRSpec spectra matching templates and detected proper motions of 49 and 24 mas/yr.
citing papers explorer
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Expanding the High-z Supernova Frontier: "Wide-Area" JWST Discoveries from the First Two Years of COSMOS-Web
JWST difference imaging from COSMOS-Web and PRIMER has yielded 68 high-redshift supernovae including a core-collapse event at z>3 and a Type Ia at z>2, demonstrating the feasibility of wide-area time-domain searches in the early universe.
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NEFERTITI: Linking early galaxy formation to the assembly of the Milky Way
NEFERTITI simulations show that the Milky Way's most metal-poor stars largely come from a handful of accreted massive dwarf galaxies, while reproducing the JWST Hebe galaxy at z~11 as a pure Population III system.
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The Pristine HeII Emitter near GN-z11: Constraining the Mass Distribution of the First Stars
High-redshift HeII emitter observations confirm a >50% PopIII stellar mass fraction and favor top-heavy IMFs for the first stars with total masses 2e4 to 6e5 solar masses.
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Metal Enrichment by the First Stars Exploding at the Lower Energy Limit of Pair-Instability Supernovae
Low-energy PISNe from 140 solar-mass Pop III stars produce second-generation stars at median [Fe/H] ~ -5.5 with odd-even patterns, but their absence from EMP observations disfavors PISNe as the main early enrichment channel.
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Two Exciting High-redshift Galaxy Candidates Turn Out to Be Two Exciting Ultra-cool Brown Dwarfs
Two high-redshift galaxy candidates are reidentified as ultra-cool Y-type brown dwarfs at ~500 pc based on NIRSpec spectra matching templates and detected proper motions of 49 and 24 mas/yr.