James Webb Space Telescope Detects Highly Ionized Atoms Presumably Surrounding a Neutron Star From the Remnants of Supernova 1987A

NASA's James Webb Space Telescope (JWST) spied on a powerful source of X-ray it detected from the remains of supernova 1987A. The blue region was believed to be highly ionized atoms surrounding an unseen neutron star.

JWST Detects Neutron Star From Remnants of Supernova 1987A

The question of whether the iron core of the blue supergiant star that gave rise to 1987A shrunk all the way down to a black hole or disintegrated into an extremely dense neutron star has long puzzled scientists. The neutron star theory is supported by the fact that neutrinos were able to escape the event, but what was left behind has not yet been identified. This is partially due to the dense dust cloud that envelops the region, formed by the outer layers of the initial star, which are currently moving away from the explosion at a speed of 10,000 km/s.

Compared to other wavelengths, infrared light passes through dust more readily. Thus, the James Webb Space Telescope (JWST), is ideally equipped to see 1987A from the cloud using its infrared eyes.

Astronomer Patrick Kavanagh and his colleagues used JWST to record light that had traces of sulfur and argon in the dusty center region. These elements had been ionized, which indicates that some of their electrons had been removed, and this was telling.

"To produce these ions, you need a source of high-energy [X-rays]," according to coauthor and Stockholm University astronomer Claes Fransson. "What is causing this ionization, is the question.'"

The team believes that there are two possibilities. First, a pulsar, a highly magnetized neutron star that produces intense radiation beams similar to those observed in the considerably closer Crab Nebula, the relic of a roughly 1,000-year-old supernova, may have been left behind by supernova 1987A. On the other hand, the X-rays might originate from a regular neutron star, which would radiate heat equivalent to a million degrees Celsius on its newly formed surface.

According to Aravind Pazhayath Ravi, an astrophysicist at the University of California, Davis, who was not involved in the investigation, this is some of the strongest indirect evidence confirming the presence of a neutron star.

Although it is not yet a direct detection, it adds to the historical data collected by devices like the Atacama Large Millimeter/submillimeter Array.

Astronomers will gain insight into the internal structure of such strange objects if they can directly catch light from the neutron star. This will allow them to compare older neutron stars elsewhere in the universe to one spotted shortly after it was born. For that, Ravi adds, the clouds around the remnant of 1987A will likely need to thin out considerably further, which should happen in the next 10 years or so.

"It's eventually going to happen that we'll have the photograph of the youngest ever observed neutron star," he added.

What Is a Neutron Star?

When a big star runs out of fuel and collapses, neutron stars are born. Every proton and electron in the star's core are crushed together to become neutrons when the core collapses. These freshly produced neutrons have the ability to halt the collapse of a collapsing star and leave behind a neutron star if the star's core is between one and three solar masses.

The result of this collapse is the densest known object: a sun-sized object with the mass of a metropolis compressed inside. The diameter of these star remnants is around 20 kilometers (12.5 miles). A sugar cube made of neutron star material would weigh as much as a mountain on Earth-roughly one trillion kilograms, or one billion tons.

Since neutron stars originated as stars, they can be found sporadically in the same locations as stars throughout the galaxy. They can also be discovered alone or in binary systems with a companion, just like stars.

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