The most powerful magnetic field ever observed is located 6,500 light years from Earth’s solar system in the Milky Way.
The groundbreaking research was made by Italian scientists u-sing the European Space Agency’s Xmm Newton Space Telescope. Astronomers estimate that it produces a magnetic field around 20 trillion times stronger than a standard refrigerator door magnet. The study marks the first time humans have directly witnessed the cosmic phenomenon kno-wn as magnetar (the dead core of a once massive star that has collapsed in on itself): a neutron star with an extremely powerful magnetic field.
With a mass greater than that of the Sun, magnetars are typically around 20 kilometers in diameter. Normally, this kind of interior’s substance would have a mass of over 100 million tons.
Unlike typical neutron stars, magnetars rotate slowly, completing a rotation once every one to 10 seconds as opposed to less than one second for an average neutron star. Its resulting magnetic field generates very intense bursts of X-rays and gamma ra-ys, with a very short active life of roughly 10,000 years.
The researchers from Pavia’s Iuss University and the National Astrophysics Institute (Inaf), the Italian group coordinated by the astrophisic Andrea Tiengo, discovered it was roughly a 100 times lower than for typical magnetars. By measuring the rate at which the spin of a magnetar de-clines, astronomers calculated the magnetic field.
Understanding these results was very difficult. “However – told Tiengo – we suspected that Sgr 0418 was hiding a much stronger magnetic field, out of reach of our usual analytical techniques”. By searching the variations in the X-rays given off by the magnetar as it rotates, they reached the new result. “We are now able to probe substructure on the surface and see that the field is very strong locally”.
The spectral data provided by Xmm-Newton, combined with a new way of analyzing the data, allowed to make the first detailed measurements of the magnetic field of a magnetar, confirming it as one of the largest va-lues ever measured in the universe”.
Sgr 0418 was first discovered in 2009 by Nasa’s Fermi space telescope and the Russian Ko-ronas-Photon observatory.
The new technique now may help researchers discover other hidden magnetars and reveal mo-re about those that have already been identified. Moreover, the theoretical model will be useful to study the behavior of subjects submitted to so intense magnetic fields, impossible to reproduce in the laboratory.
The innovative Italian research was published in the magazine Nature.
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