article epub_ahead yes Zihao Li author Koki Kakiichi author Lise Christensen author Zheng Cai author Valentina D’Odorico author Jorryt J Matthee author 7439a258-f3c0-11ec-9501-9df22fe067200000-0003-2871-127X Daichi Kashino author Rongmon Bordoloi author Ruari Mackenzie author Trystyn A.M. Berg author Irene Vanni author Stefania Salvadori author Alessandra Venditti author Shiwu Zhang author Sarah E.I. Bosman author Eduardo Bañados author Frederick B. Davies author Xiaohui Fan author Hyunsung D. Jun author Xiangyu Jin author Mingyu Li author Sofía Rojas-Ruiz author Feige Wang author Jinyi Yang author Siwei Zou author Huanian Zhang author Yongda Zhu author JoMa department The first generation of stars, known as population III (Pop III), formed from primordial gas consisting solely of hydrogen and helium and is believed to have emerged only a few hundred million years after the Big Bang. Detecting the chemical enrichment of metal-poor circumgalactic gas offers a promising way to trace the enrichment signature of Pop III stars. Along the sight line to the quasar SDSS J0100+2802, a metal absorber at z = 5.945, showing over-abundant carbon and silicon compared with solar, has been reported to be consistent with the enrichment pattern of Pop III stars. Here, using data recorded by the James Webb Space Telescope, we report the discovery of an unusually metal-poor galaxy overdensity of 17 members (mean metallicity ~3% of solar) near this metal absorber, which is ~0.4 dex more metal-poor than coeval galaxies in similarly overdense environments. This less chemically evolved system may have provided favourable conditions for preserving the absorption signatures of Pop III enrichment. We infer a minimum dark matter halo mass of log(Mh,min/M⊙) = 10.68+0.93 −1.72, supporting late-time Pop III formation at the outskirts of atomic hydrogen cooling haloes. Our findings open a promising observational pathway to identifying the chemical imprints of the first stars and constrain the conditions for their formation. Springer Nature2026 eng 2397-336610.1038/s41550-026-02993-5 Z. Li, K. Kakiichi, L. Christensen, Z. Cai, V. D’Odorico, J.J. Matthee, D. Kashino, R. Bordoloi, R. Mackenzie, T.A.M. Berg, I. Vanni, S. Salvadori, A. Venditti, S. Zhang, S.E.I. Bosman, E. Bañados, F.B. Davies, X. Fan, H.D. Jun, X. Jin, M. Li, S. Rojas-Ruiz, F. Wang, J. Yang, S. Zou, H. Zhang, Y. Zhu, Nature Astronomy (2026). Li, Zihao, et al. “First-Star Imprints in a Metal-Poor Galaxy Overdensity near the End of Reionization.” <i>Nature Astronomy</i>, Springer Nature, 2026, doi:<a href="https://doi.org/10.1038/s41550-026-02993-5">10.1038/s41550-026-02993-5</a>. Li, Z., Kakiichi, K., Christensen, L., Cai, Z., D’Odorico, V., Matthee, J. J., … Zhu, Y. (2026). First-star imprints in a metal-poor galaxy overdensity near the end of reionization. <i>Nature Astronomy</i>. Springer Nature. <a href="https://doi.org/10.1038/s41550-026-02993-5">https://doi.org/10.1038/s41550-026-02993-5</a> Li Z, Kakiichi K, Christensen L, et al. First-star imprints in a metal-poor galaxy overdensity near the end of reionization. <i>Nature Astronomy</i>. 2026. doi:<a href="https://doi.org/10.1038/s41550-026-02993-5">10.1038/s41550-026-02993-5</a> Li, Zihao, Koki Kakiichi, Lise Christensen, Zheng Cai, Valentina D’Odorico, Jorryt J Matthee, Daichi Kashino, et al. “First-Star Imprints in a Metal-Poor Galaxy Overdensity near the End of Reionization.” <i>Nature Astronomy</i>. Springer Nature, 2026. <a href="https://doi.org/10.1038/s41550-026-02993-5">https://doi.org/10.1038/s41550-026-02993-5</a>. Z. Li <i>et al.</i>, “First-star imprints in a metal-poor galaxy overdensity near the end of reionization,” <i>Nature Astronomy</i>. Springer Nature, 2026. Li Z, Kakiichi K, Christensen L, Cai Z, D’Odorico V, Matthee JJ, Kashino D, Bordoloi R, Mackenzie R, Berg TAM, Vanni I, Salvadori S, Venditti A, Zhang S, Bosman SEI, Bañados E, Davies FB, Fan X, Jun HD, Jin X, Li M, Rojas-Ruiz S, Wang F, Yang J, Zou S, Zhang H, Zhu Y. 2026. First-star imprints in a metal-poor galaxy overdensity near the end of reionization. Nature Astronomy. 230962026-10-11T22:02:07Z2026-10-14T06:42:17Z