Scientists have confirmed the fate of a star that underwent a dazzling supernova visible from Earth over three decades ago: It transformed into a neutron star, one of the most peculiar entities in the universe.
In 1987, a star in a neighboring galaxy experienced a supernova event, and its fiery end was observable in Earth’s night sky for months without the aid of telescopes. Scientists predicted that following the collapse of its core, the remaining material would either form a black hole, from which nothing can escape, or a neutron star, the most dense object in the universe aside from a black hole.
The challenge arose due to the extensive debris, hindering astronomers from seeing beyond the dust. However, NASA's Webb Space Telescope overcame this obstacle by utilizing infrared light, revealing two distinct chemical markers — argon and sulfur — characteristic of a pulsating, exceptionally hot neutron star, as detailed in a study published Thursday in the journal Science.
Given the recent and meticulously monitored nature of the explosion, this finding is poised to enhance astronomers' comprehension of this peculiar cosmic phenomenon and its precursors, which played a crucial role in dispersing essential elements like carbon and iron throughout the universe.
Measuring a mere 12 miles (20 kilometers) from one end to the other, yet boasting a weight equivalent to 1 1/2 times that of our sun, this neutron star is densely packed with minimal space between its atomic components. Scientists noted that the aftermath of the supernova event known as 1987A probably represents the sole instance in modern astronomy where the birth and initial stages of a neutron star have been directly observed, despite the existence of closer but older examples within our own galaxy.
“Besides the black hole, these are the most exotic objects we have in the universe,” stated Claes Fransson, the lead author and an astrophysicist at Stockholm University in Sweden. “We know about these objects from the 1960s, but we haven’t seen any of them being really formed.”
Images of the remote supernova remnant reveal what Fransson describes as "a ring of pearls" surrounding a dust cloud. Within the midst of that dust lies the neutron star, he noted.
For quite some time, scientists had hypothesized that the collapsed core had evolved into a neutron star. However, the data collected by the Webb telescope, despite not directly capturing an image of the neutron star, offers a fairly conclusive confirmation, according to Fransson and other experts.
Stanford University astrophysicist Roger Blandford, who was not involved in the study, expressed that the argument supporting the existence of a neutron star is compelling.
Due to the supernova explosion's recent occurrence and proximity, it “is ‘a gift that keeps on giving’, teaching us about neutrinos, the evolution of stars and now what happens following the explosion,” stated Blandford in an email.
