The Fermi Gamma-ray Space Telescope has detected an extraordinarily luminous supernova, designated SN 2017egm, which erupted approximately 440 million light-years away from Earth. Researchers have posited that a neutron star possessing an exceptionally potent magnetic field—a magnetar, formed from the star’s core collapse—could have been responsible for augmenting the explosion’s energy.
As reported by Gazeta.SPb, a team of astronomers, spearheaded by Fabio Aceituno from the University of Paris-Saclay, scrutinized data from the Fermi telescope, accumulated over 16 years of observation. The scientists examined the gamma-ray emissions from six nearby hyperluminous supernovae that originated from core collapses. Evidence of such emissions was exclusively identified in SN 2017egm, thereby substantiating the hypothesis that certain supernovae can exhibit exceptional brightness not only in the visible spectrum but also in gamma rays.
Scientists remind us that core-collapse supernovae occur at the final stage of a massive star’s life. Once its fuel is depleted, the star’s core rapidly contracts, giving rise to a neutron star with a diameter of merely about 20 kilometers. According to astrophysicists’ estimates, the matter within such objects possesses immense density; a teaspoonful of neutron matter could weigh around 10 million tons. Furthermore, young neutron stars can rotate at speeds of up to 700 revolutions per second. During the contraction process, the magnetic field intensifies dramatically, and magnetars feature magnetic fields approximately a thousand times stronger than those of typical neutron stars.
Hyperluminous supernovae radiate over ten times more light than standard supernovae of their kind. One prominent theory specifically links this phenomenon to the birth of a magnetar during the explosion.
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