The universe's strongest magnets are actually stars called magnetars. They are tiny relative to most other stars, but new observations suggest that their immense magnetic fields drive some of the biggest, most spectacularly destructive events in the universe.
Gamma-ray bursts are enormous explosions that release high-energy radiation and usually last just a few seconds, but in rare cases, they last for hours. Such was the case with the gamma-ray burst, or GRB, that occurred in 2011 and led researchers to make the connection to magnetars. They reported their findings in the journal Nature.
"The new results provide good evidence for an unexpected relation between GRBs, very bright supernovae and magnetars," study co-author Paolo Mazzali of Liverpool John Moores University said in a statement. "Some of these connections were already suspected on theoretical grounds for some years, but linking everything together is an exciting new development."
Previously, scientists thought that GRBs must be caused by the collapse of stars in the neighborhood of 50 times as massive as our sun. However, observations of this unusually long and bright GRB and its associated supernova proved this to be impossible.
Instead, researchers found magnetars to be the only plausible driver of the GRB. Magnetars are a type of neutron star, the smallest and densest type of star known to exist. Neutron stars often have a radius of less than 10 miles, yet they contain more mass than our sun. Magnetars are different from other neutron stars in that they spin hundreds of times per second and have a much stronger magnetic field — stronger than that of anything else in the known universe.
The observations of the GRB and its aftermath were made using the GROND instrument on the MPG/ESO 2.2-metre telescope at La Silla, Chile, and also with the X-shooter instrument on the ESO's Very Large Telescope.
