Mystery of the missing core

Abstract

Stars are blowing up all the time, but supernova SN 1987a is exceptional, as it was visible to the naked eye in the Southern Hemisphere. Neutrinos detected 23hours before the light arrived on Earth suggest the formation of a compact object usually a neutron star for progenitor stars in this mass range (roughly 20 solar masses). But despite continued monitoring and no shortage of speculation, nobody has been able to resolve any core. Now GiovannaZanardo and co-authors provide tantalizing evidence for a pulsar a rotating neutron star with a strong magnetic field. The team used information from two southern telescopes, the Atacama Large Millimeter/submillimeter Array (ALMA) and the Australia Telescope Compact Array (ATCA), to separate the radiation from the inner core of the remnant from that dueto the expanding shock wave. The eastern lobe shows shock waves of higher velocity, whereas an excess synchrotron emission consistent with a compact source producing shocked magnetized particle wind as from a pulsar lies to the west of the remnant.