Starquakes: The Birth of Cosmic Radio Signals ✛ ✎

Original: "Crustal Quakes Spark Magnetospheric Blasts: Imprints of Realistic Magnetar Crust Oscillations on the Fast Radio Burst Signal"
arXiv:2508.18033 · 2025-08-25 · arXiv non-exclusive · independent analysis · 1 min
For the first time, simulations show how the shaking of a magnetar's crust gives rise to powerful bursts of radio emission.

Magnetars are a rare type of neutron stars, the remnants of massive stellar deaths. Their magnetic fields are billions of times stronger than Earth's magnets. The thin crust of such a star occasionally cracks, triggering a cascade: the field, like a taut string, vibrates, accelerating trapped particles to light speed. In hundredths of a second, as much energy is released as the Sun emits in hundreds of thousands of years. We detect this as a fast radio burst — a mysterious signal from deep space.

Bring a magnetar as close as the Moon, and its field would wipe all bank cards' magnetic data.

The new model for the first time linked crustal quakes to the magnetic field's response. It turned out that repeated shudders create a rhythmic pattern of bursts, reminiscent of signals from pulsars — stellar lighthouses discovered by Jocelyn Bell Burnell in 1967. Magnetars themselves are a legacy of predictions by Fritz Zwicky in the 1930s.

Waves along the magnetic lines travel like tremors along a guitar string.

The dance of starquakes unveils the nature of the most powerful radio bursts in the universe.

A magnetar's magnetic field is billions of times stronger than Earth's. If it were at the Moon's distance, not just cards but any magnetic recording would fly.

In Carl Sagan's 'Contact,' the alien signal turned out to be a message; fast radio bursts were also initially mistaken for greetings from extraterrestrial civilizations.

B_{\rm fast} \propto (r/r_*)^2
The amplitude of fast magnetosonic waves grows quadratically with distance from the star, because the dipole field falls off as a cube, while the energy flux is conserved.
Scientists
Max PlanckAlbert EinsteinEnrico FermiPaul DiracJohn Henry PoyntingSubrahmanyan Chandrasekhar
Concepts
fast radio burst radio pulse magnetar magnetar pulsations in grb magnetic storm stellar flares Westerly wind burst magnetic wave alfven wave electromagnetic radiation solar wind waves magnetorotational supernova flare pulsar earthquake pulsar phenomena x ray pulse phonon magnetism solar eruption acoustic oscillations