Magnetars
Neutron stars with the most powerful magnetic fields in the universe.
A magnetar is a type of neutron star with an extremely powerful magnetic field, typically around 10⁹ to 10¹¹ tesla. The decay of this magnetic field powers the emission of high-energy electromagnetic radiation, particularly X-rays and gamma rays. Magnetars are distinguished from other neutron stars by their stronger magnetic fields and slower rotation, with most observed magnetars rotating once every two to ten seconds.
- type
- Neutron star
- magnetic_field_strength
- ~10⁹ to 10¹¹ T
- typical_diameter
- ~20 km
- typical_mass
- ~1.4 solar masses
- known_for
- Extremely powerful magnetic fields; sources of soft gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs); possible source of fast radio bursts (FRBs)
Lore & Background
Over the following decade, the magnetar hypothesis became widely accepted and was extended to explain anomalous X-ray pulsars (AXPs). Magnetars are formed by the collapse of a star with a mass 10–25 times that of the Sun. Their strong magnetic fields are thought to result from a magnetohydrodynamic dynamo process in the turbulent, dense conducting fluid that exists before the neutron star settles into equilibrium. An alternative model suggests they simply result from the collapse of stars with unusually strong magnetic fields.
Reader's Guide
Magnetars represent an extreme state of matter and magnetic fields in the universe. At a distance halfway from Earth to the Moon, a magnetar could erase information from the magnetic stripes of all credit cards on Earth. The study of magnetars has deepened understanding of neutron star physics and high-energy astrophysics.
Did You Know?
- A magnetar's magnetic field is about a trillion times more powerful than Earth's geomagnetic field.
- In a magnetic field of 10¹⁰ tesla, a hydrogen atom becomes 200 times as narrow as its normal diameter.
- It is estimated that about one in ten supernova explosions results in a magnetar rather than a standard neutron star or pulsar.
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