Gold Isn't Just from Neutron Stars: Where's the Hidden Source? ⚡ экспресс
Observations of the neutron star merger GW170817 and its associated kilonova confirmed that such events are an important source of r-process elements. However, data on the chemical composition of stars in the Milky Way's disk indicate the need for additional enrichment channels. The study combined data from gravitational-wave observatories LIGO-Virgo-KAGRA, short gamma-ray bursts, Galactic pulsars, and observed Eu/Fe versus Fe/H relationships to assess the contribution of neutron star–black hole mergers and rapidly merging binary neutron stars to the r-process content in the Galactic disk. The analysis was performed within a unified Bayesian model, accounting for uncertainties in merger rates, delay time distributions, mass ejecta as functions of masses and spins, and stellar abundances. It was found that neither of these channels can dominate as an additional source without strongly diverging from existing observations and theoretical expectations. These results narrow the range of possible r-process suppliers and emphasize the necessity of contributions from non-merger processes.
The universe is a giant cosmic kitchen, where chemical elements are “cooked” inside stars and in epic collisions. The heaviest ones, like gold and platinum, need the most extreme conditions. Astronomers thought the only “chefs” for these delicacies were neutron star mergers—the ultra-dense remnants of dead stars. But when scientists weighed all the gold in the Milky Way and compared it to the “output” of such mergers, they found a shortfall—a serious one.
They checked every known recipe. They even considered especially fast neutron star mergers and pairs of black holes and neutron stars, which also produce heavy elements. They added data from gravitational wave detectors—ripples in spacetime—along with spectroscopic observations (analyzing stars’ chemical makeup from their light) and powerful gamma-ray bursts. But even then the “dish” doesn’t add up: there should be way more precious metals.
That means another, still unidentified “cook” is at work in the cosmic kitchen. Maybe it’s a rare type of supernova explosion—a magnetar-powered hypernova, where matter is compressed and heated to unimaginable temperatures. Or the source might be hiding in collisions of even more exotic objects. The gold mystery remains unsolved, and astro-detectives keep hunting for the hidden ingredient.
🎯 In 2017, a neutron star merger was recorded that ejected gold several times more massive than Earth.