In June 2024, the CHIME radio telescope recorded over 700 radio bursts per hour from source FRB 20240114A. Such a hyperactive repeater releases in one hour nearly all the magnetic energy of a typical magnetar (a neutron star with an ultra-strong field).

This is just one of dozens of mysterious transients that have puzzled astrophysicists for years: ultra-luminous supernovae, flaring hundreds of times brighter than normal, anomalous X-ray pulsars, and luminous fast blue optical transients. Fritz Zwicky had already proposed that neutron stars are born in supernovae, but the mechanism of their magnetization remained a mystery. Traditional models tried to derive the magnetic fields from the rapid rotation of a newborn neutron star. But such 'spun-up' objects are born a hundred times less often than magnetars are observed.

A new perspective comes from Ouyed (2026). Long stellar evolution (a star's life from birth to collapse) gives rise to neutron stars, but the key is not rotation but mass. A neutron star born with a mass above the critical threshold of about 2.1 solar masses hides in its depths a quark core — a ferromagnetic phase akin to a permanent magnet. While the star spins rapidly, centrifugal forces prevent the matter from rearranging. It's a sleeping volcano. When the slowing rotation reduces pressure, quark deconfinement (the transition of neutrons into free quarks) occurs — an explosive transformation of the core. Suddenly, the quarks align in ferromagnetic order (spontaneous magnetization), and an exotic Phase transition takes place (a change from one state of matter to another). Inside, a field of $10^{18}$ Gauss is generated. On the surface, a magnetar emerges with a field on the order of $10^{15}$ G.

Two parameters — the critical mass and a critical rotation period of about 5.5 milliseconds — determine the star's fate. If everything happens inside an optically thick shell, we observe an ultra-luminous supernova. If the period is still short and the radiation pierces the remnant, we get a fast radio burst. The delay between collapse and quark-nova can range from days to millions of years, explaining bursts in the most unexpected places — from the outskirts of elliptical galaxies to globular clusters. Moreover, neutron-rich outflows synthesize heavy elements via the r-process (rapid neutron capture) and produce a kilonova — an infrared glow previously attributed only to neutron star mergers. In an extended model, a quark-nova can also launch a relativistic jet, becoming a gamma-ray burst source, and its gravitational-wave signal makes it a target for multi-messenger astronomy (simultaneous observations across different messengers).

This picture, backed by population synthesis (computer simulations of millions of stars) and Bayesian analysis, resolves a half-century-old contradiction. Subrahmanyan Chandrasekhar introduced a mass limit for white dwarfs; here, a critical mass separates the fates of neutron stars. Decades after Jocelyn Bell Burnell discovered the first pulsars, it becomes clear that neutron stars are far more diverse. In the coming years, the model can be tested: searching for infrared kilonovae from luminous blue transients, monitoring old ultra-luminous supernovae for radio awakening. If mass truly governs magnetism, then every magnetar is a former massive neutron star, not a rare lucky one. And someday, a new hyperactive repeater caught by CHIME will not only flash in radio but also emit an infrared kilonova signature — and the sleeping volcano will finally awaken in our imagination.