Science for All | A brand new supply of gold within the universe?

Newly refined gold granules earlier than they’re processed into gold bars on the ABC Refinery smelter in Sydney, Australia, Wednesday, April 30, 2025. (Picture used for illustration solely)
| Photograph Credit score: Mark Baker

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In a brand new paper revealed in The Astrophysical Journal Letters, a crew of researchers led by Anirudh Patel of Columbia College has reported that the universe might have one other strategy to produce the valuable factor gold — which scientists have thus far believed has been produced solely within the cataclysmic collisions of ultra-dense worlds referred to as neutron stars.

Understanding the place totally different parts within the universe come from helps scientists perceive how the universe’s chemical make-up has modified by time. The early universe solely had hydrogen, helium, and hint quantities of lithium. All different parts have been created later in stars, cosmic explosions, and laboratory experiments. Mapping the sources tells us how galaxies, stars, and planets took form over time. Understanding the sources may also reveal how usually a component was produced and the way the presence of a component influenced the supply’s personal evolution.

The crew reported the primary direct observational proof of a course of referred to as r-process nucleosynthesis in a strong flare emitted by a physique referred to as a magnetar in 2004. Nearly a day after the flare, the magnetar emitted robust gamma rays, which NASA’s Compton Gamma Ray Observatory recorded. Per the crew, the delayed emission was inconsistent with customary flare afterglows and contained proof of radioactive decay from r-process nuclei.

Magnetars are neutron stars with extraordinarily robust magnetic fields. Typically they launch massive bursts of vitality in flares.

The vitality ranges within the delayed emission and the way it modified in time have been discovered to be in keeping with the decay signatures of radioactive isotopes wealthy in neutrons produced within the speedy neutron-capture course of, or r-process. The crew used fashions to conclude that 1.9 septillion kg of r-process materials ejected at near the pace of sunshine may clarify the delayed emission.

This implies some magnetar flares can eject neutron-rich matter into house, the place it goes by r-process nucleosynthesis to create heavy parts like gold. To this point, physicists have believed that gold has predominantly been produced in mergers of neutron stars, which scientists research utilizing house telescopes and gravitational wave detectors. Patel et al. additionally instructed that the universe might have had gold atoms sooner because the cosmos may have had magnetars earlier than colliding neutron stars.

The authors additionally thought-about some different explanations — together with noise within the measuring devices and devices misreading the flare’s afterglow — and dominated them out by comparisons with different knowledge and detailed simulations.

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