Invisible Lighthouse: Magnetar Pulse in a Gamma-Ray Burst ⚡ экспресс
It is generally assumed that the outcome of compact star mergers is a hyper-accreting black hole, producing a gamma-ray burst shorter than 2 seconds. However, observations of GRB 211211A and GRB 230307A—long-duration bursts from mergers—have challenged this model, suggesting the possible birth of a rapidly spinning, highly magnetized neutron star: a millisecond magnetar. The study presents strong but not yet conclusive evidence of a periodic gamma-ray signal at 909 Hz within a short time window (160 ms) of GRB 230307A, during the transition from central jet emission to high-latitude emission. This frequency matches the typical spin period of a millisecond magnetar. If real, its timing and spectral properties align with a model of asymmetric mini-jets emerging from a jet dominated by Poynting flux dissipation, supported by the burst's energy-dependent light curve.
Some cosmic explosions—gamma-ray bursts—last just a couple of seconds, but GRB 230307A glowed for several minutes. Usually such an explosion gives birth to a black hole, but the prolonged glow hinted at a different outcome: perhaps a magnetar emerged—a hyper-magnetized neutron star spinning at a furious rate.
Telescopes caught a fleeting rhythmic signal in this burst—like the beam of a distant lighthouse momentarily sweeping over Earth. The frequency of 909 hertz means 909 rotations per second: a typical tempo for a newborn pulsar. The signal lasted just 160 milliseconds, shorter than a blink, but in that time the magnetar released as much energy as the Sun does in a million years.
This ‘lighthouse’ signal confirms for the first time that it is a neutron star, not a black hole, that can power long gamma-ray bursts. Such observations will help unravel how the most extreme engines in the Universe work.
🎯 A neutron star is the core of a dead star, compressed to the size of a city: a teaspoon of its material would weigh billions of tons.
🎬 In the novel 'Dragon's Egg', Robert Forward imagined life on the surface of a neutron star, where monstrous gravity speeds up time thousands of times.