At the heart of the Milky Way spins a stellar bar — an elongated cluster, like a rotating paddle. Its gravity creates a rhythmic field around it, like waves from a speedboat. Stars at the Galaxy's edge, caught in resonance, ride this wave: their orbital period matches the bar's rotation, keeping them in step for ages.
Dark matter clumps, clumps of dark matter, drift through the Galaxy and disturb this delicate rhythm. Like oncoming boats, they create interference, breaking the synchronization. A mass of such clumps, predicted by the standard model, would have long washed out the resonant wave.
Observations show the resonance has survived. So the actual number of clumps is at least three times lower than theory suggests. Most likely, tidal forces in the Galaxy tear them apart. Thus, the stellar rhythm becomes a natural dark matter detector, working for billions of years — without a single direct contact. This method continues the search begun by Vera Rubin and Fritz Zwicky, who first pointed to the invisible mass.
Resonance with the central bar is like the familiar dance of Trojan asteroids with Jupiter — except here the 'conductor' is not a planet, but the entire Galaxy.