Supernova SN 1987A took place in the Large Magellanic Cloud and became visible to Earth in 1987. This was the closest supernova in 400 years. At the center of the explosion, astronomers have long observed a blob of material. For decades, however, scientists wondered whether it was shrouding a neutron star or a black hole. As reported in The Astrophysical Journal, observations from the Atacama Large Millimeter/submillimeter Array (ALMA) strongly support the neutron star scenario.
“We were very surprised to see this warm blob made by a thick cloud of dust in the supernova remnant,” co-author Mikako Matsuura, from Cardiff University and a member of the team that found the blob with ALMA, said in a statement. “There has to be something in the cloud that has heated up the dust and which makes it shine. That’s why we suggested that there is a neutron star hiding inside the dust cloud.”
A peculiar feature of the blob is its brightness, which suggests it's being heated by something formidable. At one point, the team even thought that it was too bright to be a neutron star, but a contemporary study actually predicted several observed features. This was also published in The Astrophysical Journal.
“I was halfway through my Ph.D. when the supernova happened; it was one of the biggest events in my life that made me change the course of my career to try to solve this mystery. It was like a modern holy grail,” explained lead author Dany Page from the National Autonomous University of Mexico. “In spite of the supreme complexity of a supernova explosion and the extreme conditions reigning in the interior of a neutron star, the detection of a warm blob of dust is a confirmation of several predictions.”
The object, at only 25 kilometers (15.5 miles) across, is expected to weigh a few times the mass of the Sun. At 33 years old, this is the youngest known neutron star.
This latest work builds on years of observations from ALMA of SN 1987A, including a recent 3D reconstruction of what it's like to fly inside the supernova.