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Astronomers have discovered a jet of fast moving material that they believe would have been propelled to the outside of a type of neutron star.
Observed with the help of Karl G. Jansky's very large network (VLA) of the National Science Foundation, the discovery is strange, as it was previously thought that the star was unable to launch such a jet.
As a result, scientists explained, they might have to fundamentally review their ideas about the origin of such jets because it is the "wrong" type of star.
Neutron stars are super-dense objects, the remains of massive stars that have exploded like supernovas. When they are in binary pairs with "normal" stars, their powerful gravity can move the material away from their companions.
This material forms a disk, called accretion disk, rotating around the neutron star. The jets of matter are propelled at the speed of light, perpendicular to the disc.
"We have seen jets coming from all types of neutron stars extracting materials from their companions, with one single exception." Never before have we seen a jet coming from a single source. neutron star with a very strong magnetic field, "said Jakob van den. Eijnden from the University of Amsterdam.
"This led to a theory that strong magnetic fields prevent the formation of jets."
However, the new discovery contradicts this theory.
Narrative animation describing the results and their meaning (English) of ICRAR on Vimeo
The object studied by scientists called Swift J0243.6 + 6124 (Sw J0243). It was discovered on October 3, 2017 by NASA's Neil Gehrels Swift observatory, while the object was emitting a burst of X-rays.
The object is a slow-spinning neutron star that extracts material from an associated star that is probably much larger than the Sun. The VLA observations began a week after the discovery of Swift and continued until January of this year.
The fact that the emission of the object at radio and radio wavelengths weakened over time and the characteristics of the radio program itself convinced astronomers that they saw radio waves produced by a jet .
"This combination is what we see in other systems producing jets, alternative mechanisms simply do not explain it," van den Eijnden said.
Current theories on jet formation in systems such as Sw J0243 indicate that the jets are launched by magnetic field lines anchored in the inner parts of the accretion discs.
But in this scenario, if the neutron star has a very strong magnetic field, this field is too powerful and prevents the jet from forming.
"Our obvious discovery of a jet in Sw J0243 refutes this long-standing idea," added van den Eijnden.
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