SN 1987A is the only supernova visible to the naked eye in the last 400 years and the most studied supernova in history. The event was a core-collapse supernova, meaning the compacted remains at its core formed either a neutron star or a black hole. Evidence for such a compact object has long been sought, and while indirect evidence for the presence of a neutron star has previously been found, this is the first time that the effects of high-energy emission from the probable young neutron star have been detected.
SN 1987A was first observed on February 23, 1987 at the edge of the Large Magellanic Cloud, some 163,000 light-years away.
It was the first naked-eye supernova to be observed since Johannes Kepler witnessed a supernova over 400 years ago.
About two hours prior to the first visible-light observation of SN 1987A, three observatories around the world detected a burst of neutrinos lasting only a few seconds.
The two different types of observations were linked to the same supernova event, and provided important evidence to inform the theory of how core-collapse supernovae take place.
This theory included the expectation that this type of supernova would form a neutron star or a black hole.
Astronomers have searched for evidence for one or the other of these compact objects at the center of the expanding remnant material ever since.
Indirect evidence for the presence of a neutron star at the center of the remnant has been found in the past few years, and observations of much older supernova remnants — such as the Crab Nebula — confirm that neutron stars are found in many supernova remnants.
However, no direct evidence of a neutron star in the aftermath of SN 1987A had been observed, until now.
“From theoretical models of SN 1987A, the 10-second burst of neutrinos observed just before the supernova implied that a neutron star or black hole was formed in the explosion,” said Stockholm University astronomer Claes Fransson, lead author of the…
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