Sun Contains 55 Percent More Silver Than Previously Estimated

Closing the Gap on Solar Silver

For years, astronomers struggled with a persistent mystery: the Sun appeared to hold significantly less silver than the primitive meteorites known as CI chondrites. Because both the Sun and these meteorites formed from the same primordial cloud of gas and dust approximately 4.6 billion years ago, scientists expected their chemical compositions to align. The persistent shortfall led some to question whether unknown physical processes had altered the Sun’s makeup over eons, or if current measurement models were simply failing to capture the full picture.

New research led by Sema Caliskan at Uppsala University suggests the latter. By applying a more sophisticated approach to modeling the solar atmosphere, the team found that the missing silver was likely present all along, obscured by the limitations of earlier, simplified one-dimensional models. The new calculation indicates the Sun contains 55 percent more silver than previously thought, a finding that brings solar composition into much closer harmony with the chemical signatures found in ancient meteorites.

Advanced Modeling and the Tetralith Supercomputer

The breakthrough required moving beyond the assumption of local thermodynamic equilibrium—a standard but limited approach used in previous studies. Instead, Caliskan and her colleagues developed a three-dimensional model that accounts for the turbulent movement of rising hot material and sinking cool gas on the Sun’s surface. Crucially, the team incorporated complex non-equilibrium effects that describe how silver atoms absorb radiation and interact with surrounding particles.

Because some necessary atomic data did not exist, the researchers first had to calculate missing transition data and collision rates. This rigorous preparation allowed them to simulate 57 atomic energy levels, providing a level of detail that earlier, simpler simulations could not achieve. The study, published in the journal Astronomy & Astrophysics in July 2026, demonstrates that radiation actually weakens silver’s spectral lines, leading to an underestimation of the element when using traditional methods.

Why Trace Elements Matter for Galactic History

While hydrogen and helium constitute 98.5 percent of the Sun’s mass, the remaining 1.5 percent—which includes elements like silver, iron, and carbon—serves as a vital record of cosmic history. These heavy elements are forged inside stars and during supernova explosions, eventually seeding the gas and dust that form subsequent generations of stars and planets.

By refining the accuracy of these measurements, astronomers gain a better understanding of how heavy elements are distributed throughout the Milky Way. As Caliskan noted, the Sun acts as one of astronomy’s key reference points for understanding other stars. The team now plans to apply this advanced modeling technique to other stellar bodies to further map the chemical evolution of the galaxy.

The resolution of the silver mystery marks a significant step forward in stellar astrophysics, confirming that the Sun’s chemical origin remains consistent with the materials that built the rest of the solar system.