Why does a neutron star's X-ray bursts change personality during outbursts?

The Rapid Burster, a neutron star in a binary system, produces type-II X-ray bursts that change character during outbursts—sometimes short and frequent, sometimes long and energetic. Researchers found the bursts follow a relaxation oscillator pattern where energy scales with recurrence time, but the relationship breaks differently depending on which mode the star is in, suggesting distinct physical processes control the explosions.