Magnetars: The Most Magnetic Objects in the Universe

Neutron stars are already among the most extreme objects in space, but some are even more unusual. These objects are called magnetars, and they have the strongest magnetic fields known in the universe. Although they are only about the size of a city, their magnetic power and violent bursts of energy make them some of the most fascinating stellar remains astronomers have discovered.

A magnetar forms after a massive star reaches the end of its life and explodes as a supernova. The star’s core collapses under gravity, compressing an enormous amount of matter into a sphere only around 20 kilometers wide. This produces a neutron star, an object so dense that even a tiny amount of its material would weigh billions of tonnes on Earth. Magnetars are a special type of neutron star with magnetic fields far stronger than those of most others.

Scientists are still studying exactly why some neutron stars become magnetars. One explanation is that the original star’s core rotated very quickly before and during its collapse. This rapid movement, combined with electrically charged material inside the star, may have strengthened its magnetic field to an extraordinary level.

("What are neutron stars?" | Space)

A magnetar’s magnetic field can be hundreds or even thousands of times stronger than that of a typical neutron star and trillions of times stronger than Earth’s. If one were somehow brought close enough to our planet, its field could seriously affect electronics and even the structure of atoms. Fortunately, all known magnetars are extremely far away.

Magnetars are also known for sudden bursts of X-rays and gamma rays. Their magnetic fields can twist and place enormous pressure on the star’s solid outer crust. When the crust shifts or cracks, it creates a type of starquake that releases a large amount of stored magnetic energy. Some of these bursts last only a fraction of a second, while larger events can briefly become among the brightest sources of high-energy radiation in the sky.

Unlike ordinary stars, magnetars are not powered by nuclear fusion. Their most energetic activity is mainly powered by the gradual decay and rearrangement of their magnetic fields. Over time, this magnetic energy weakens, meaning magnetars are often most active when they are relatively young.

("Illustration of Magnetar" - NASA Science)

Studying magnetars helps scientists investigate conditions that cannot be recreated in laboratories on Earth. Their extreme gravity, density, and magnetic fields allow researchers to test theories about matter, radiation, and the internal structure of neutron stars. They may also help explain certain mysterious flashes of radio waves and high-energy radiation detected across space.

In conclusion, magnetars prove that a small object can contain an almost unimaginable amount of power. Though they are only the size of a city, their magnetic fields can influence matter across enormous distances and cause some of the most energetic explosions in the universe.