🌟 Using dead stars to search for ghost particles

What if dead stars became tools for detecting invisible particles? This idea drives new research utilizing white dwarfs, the remnants of stars like our Sun after the end of their life, to hunt for axions, hypothetical particles linked to dark matter.

Proposed several decades ago to solve a puzzle concerning nuclear forces, axions are now considered possible candidates for dark matter, that invisible component which represents a significant part of the cosmos. Although elusive, their existence could leave indirect imprints in stellar evolution.


The scientific team examined archived data from the Hubble Space Telescope, focusing on the white dwarfs in the globular cluster 47 Tucanae. These celestial objects constitute an ideal laboratory because they were all born simultaneously, providing a uniform sample to analyze their cooling. Subsequently, simulations were used to predict the potential influence of axions on the temperature of these stars.

Within the framework of certain models, the electrons present in white dwarfs, moving at speeds close to that of light, could generate axions. These particles would then escape, carrying energy with them and thus accelerating stellar cooling. The researchers incorporated this mechanism into simulation software in order to compare these predictions with actual observations.

No significant trace of cooling attributable to axions was detected in the results. This work made it possible to place new constraints on the interaction between electrons and axions, showing that this process, if it exists, would be extremely weak. These elements thus provide a clearer view of phenomena conceivable in the cosmos.

These observations do not rule out the existence of axions, but they guide investigations toward other avenues.