Astronomers Discover SDSS J0715-7334 the Most Pristine Star Known in the Universe Using Las Campanas Observatory

Astronomers discover the universe's most pristine star, SDSS J0715-7334, an ancient immigrant with 40 times less iron than previous record holders.

By: AXL Media

Published: Apr 3, 2026, 11:01 AM EDT

Source: Information for this report was sourced from Carnegie Institution for Science

A Rare Glimpse Into the Dawn of Stellar Formation

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The discovery of SDSS J0715-7334 represents a milestone in observational astrophysics, offering a nearly untouched record of the conditions following the Big Bang. This star belongs to the second generation of celestial objects, forming shortly after the universe transitioned from a hot soup of particles into neutral hydrogen gas. Unlike modern stars that are rich in heavy elements, this ancient object was forged from the detritus of the very first stars, which were composed solely of hydrogen and helium. By studying such pristine survivors, astronomers can effectively look back in time to understand how the first structures in the cosmos began to coalesce and ignite.

The Chemical Fingerprints of an Ancient Survivor

In the field of astronomy, all elements heavier than hydrogen and helium are classified as metals. The extreme purity of SDSS J0715-7334 is defined by its incredibly low metal content, which is 40 times more iron-poor than the previous record holder for a pristine star. According to lead researcher Alexander Ji, finding a star with such minimal heavy element concentration confirms that it formed before the cosmos was heavily seeded by repeated cycles of supernovae and stellar collisions. This chemical signature acts as a chronological marker, placing the birth of the star in a period when the universe was still in its infancy.