For some technological speculators, the universe could be considered a gold mine. But in terms of literally yielding precious metals, a more accurate description might be a factory — albeit one that operates intermittently and under both rare and extreme circumstances.
Astronomers now have a much better understanding of the cosmic conditions that create gold, platinum, and other heavy elements. They’ve identified and characterized a giant flare from a supermagnetized star that may have generated as much as 10 percent of our galaxy’s heavy elements, they report in The Astrophysical Journal Letters.
Star in Magnetic Fields
The genesis of the discovery dates to a previous event. In 2004, a space telescope captured a magnetar — a type of star wrapped in magnetic fields trillions of times as strong as Earth’s — emitting a giant flare. Although that blast of light and radioactive particles only lasted a few seconds, it released more energy than our sun does in a million years.
Astronomers identified that first flash of light. But a smaller one that peaked about 10 minutes later remained unexplained.
That second one has now been identified as the birth of heavy elements, including gold and platinum. In addition to pinpointing the cause of the second flare, the astronomers also calculated how much heavy metal the first one produced: the equivalent of a third of Earth’s mass. There has only been one other observation of such creation, but from a different source — neutron star mergers.
“This is really just the second time we've ever directly seen proof of where these elements form,” Brian Metzger, a scientist at the Flatiron Institute’s Center for Computational Astrophysics (CCA) in New York City and an author of the paper, said in a press release. “It’s a substantial leap in our understanding of heavy elements production.”
Read More: High-Definition Images Give Us Earliest Look at Birth of the Universe
Heavy Metal Creation
In the early days of the Universe relatively few elements were formed in the Big Bang. After that event, there was plenty of hydrogen and helium, as well as a dash of lithium. But most of the elements on the Periodic Table did not yet exist. Other elements gradually came into being as stars were born and died over time. But those explanations only held for the lighter elements.
While scientists thoroughly understand where and how the lighter elements are made, the production locations of many of the heaviest neutron-rich elements — those heavier than iron — remain incomplete.
Scientists theorized that heavy metals were produced in a set of rapid nuclear reactions. Astronomers confirmed the process in 2017 when they watched two neutron stars collide. That collision created the conditions for heavy metal creation.
However, since such collisions are so rare, they couldn’t account for all the heavy metals in existence. Some suspected that magnetars could also be a source, since they also contain an abundant and dense amount of neutrons. Metzger and colleagues calculated in 2024 that giant flares could also produce heavy metals. They have now confirmed it.
The Search Is On
Since magnetar flares are more common than neutron star collisions, the scientists expect to find more, now that they know where to look and what to look for. They will soon have a better tool to search for them when NASA’s Compton Spectrometer and Imager mission, launches in 2027.
Finding them will still be a challenge, though. Large magnetar flares happen every few decades in the Milky Way and about once a year across the visible universe. And astronomers will only have about 10 to 15 minutes to point a telescope at the burst once the initial signal is detected.
“It’ll be a fun chase,” said in the release Metzger.
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
The Astrophysical Journal Letters. Direct Evidence for r-process Nucleosynthesis in Delayed MeV Emission from the SGR 1806–20 Magnetar Giant Flare
Oxford Academic. Dynamics of baryon ejection in magnetar giant flares: implications for radio afterglows, r-process nucleosynthesis, and fast radio bursts
Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. He began his career in newspapers, but switched to scientific magazines. His work has appeared in publications including Science News, Science, Nature, and Scientific American.
