A nearly pristine star from the Large Magellanic Cloud
Abstract
The first stars formed out of pristine gas, causing them to be so massive that none are expected to have survived until today. If their direct descendants were sufficiently low-mass stars, such stars could exist today and would be recognizable by having the lowest metallicities (abundance of elements heavier than helium). We present the independent identification and detailed chemical analysis of the star SDSS J0715-7334, finding ultra-low elemental abundances of both iron and carbon ([Fe/H] = -4.3, [C/Fe] < -0.2) and total metallicity Z < 7.8 x 10^{-7} (log Z/Zsun < -4.3). The star's orbit indicates that it originates from the halo of the Large Magellanic Cloud. Its heavy element abundance pattern can be explained by a primordial supernova with an initial mass of 30 solar masses. This star is over ten times more chemically pristine than the most extreme high-redshift galaxies currently found by the James Webb Space Telescope. It is sufficiently metal-poor that current models of low-mass star formation require dust cooling to explain its existence.
Keywords
Cite
@article{arxiv.2509.21643,
title = {A nearly pristine star from the Large Magellanic Cloud},
author = {Alexander P. Ji and Vedant Chandra and Selenna Mejias-Torres and Zhongyuan Zhang and Philipp Eitner and Kevin C. Schlaufman and Hillary Diane Andales and Ha Do and Natalie M. Orrantia and Rithika Tudmilla and Pierre N. Thibodeaux and Keivan G. Stassun and Madeline Howell and Jamie Tayar and Maria Bergemann and Andrew R. Casey and Jennifer A. Johnson and Joleen K. Carlberg and William Cerny and Jose G. Fernandez-Trincado and Keith Hawkins and Juna A. Kollmeier and Chervin F. P. Laporte and Guilherme Limberg and Tadafumi Matsuno and Szabolcs Meszaros and Sean Morrison and David L. Nidever and Guy S. Stringfellow and Donald P. Schneider and Riley Thai},
journal= {arXiv preprint arXiv:2509.21643},
year = {2026}
}
Comments
Accepted to Nature Astronomy, author version