An exceptionally pure star, designated SDSS J0715-7334, which originated within the halo of the Large Magellanic Cloud and subsequently journeyed to our Milky Way Galaxy eons ago, has been identified by a collective of undergraduate scholars from the University of Chicago.
The Milky Way Galaxy highlighting the location of SDSS J0715-7334 with a star symbol; the continuous red line illustrates the star’s trajectory through our Galaxy; the discontinuous blue line indicates the anticipated path for a star originating from the Large Magellanic Cloud. Image credit: Vedant Chandra / SDSS Collaboration / ESA / Gaia / A. Moitinho, A. F. Silva, M. Barros, C. Barata, University of Lisbon / H. Savietto, Fork Research.
The genesis of the cosmos, marked by the Big Bang, produced an intensely hot and dense particulate plasma.
As this primordial material expanded over vast timescales, it underwent a cooling process, leading to the formation of neutral hydrogen gas.
Certain regions, characterized by greater density, eventually exerted gravitational forces that counteracted the universe’s expansion, prompting an inward collapse of matter after several hundred million years.
This aggregation gave rise to the inaugural generation of stars, which were composed solely of unadulterated hydrogen and helium.
These celestial bodies, burning with intense heat and experiencing short lifespans, seeded the cosmos with newly synthesized elements through their explosive demise, scattering these materials throughout space.
Subsequently, from this enriched cosmic dust, subsequent stellar generations emerged, incorporating a more diverse range of elements than their predecessors.
“All heavier elements in the universe, which astrophysicists categorize as metals, are the progeny of stellar phenomena, including nuclear fusion within stars, supernova events, and the cataclysmic mergers of compact stellar remnants,” stated Professor Alex Ji of the University of Chicago.
“Consequently, the discovery of a star exhibiting minimal metallic content signaled to this student cohort that they had encountered a truly remarkable celestial object.”
Possessing only 0.005% of the metallic abundance found in our Sun, SDSS J0715-7334 exhibits the lowest metallicity of any star presently cataloged, surpassing the previous record holder by more than twofold.
This star, identified within data acquired from the Sloan Digital Sky Survey (SDSS), is situated approximately 80,000 light-years distant from our planet.
An examination of its orbital characteristics indicates that it originated in the Large Magellanic Cloud and traversed into the Milky Way billions of years ago.
“This ancient interstellar wanderer offers us an unparalleled glimpse into the environmental conditions of the nascent universe,” Professor Ji commented.
“Extensive data initiatives such as SDSS significantly facilitate direct student involvement in pivotal scientific breakthroughs.”
“Our comprehensive elemental analysis of the star revealed exceedingly low abundances across all measured elements,” reported Ha Do, one of the University of Chicago students credited with this discovery.
The academic findings of the research team have been disseminated in the esteemed journal Nature Astronomy.
_____
A.P. Ji et al. A nearly pristine star from the Large Magellanic Cloud. Nat Astron, published online April 3, 2026; doi: 10.1038/s41550-026-02816-7
