Stellar remains of famed 1987 supernova found at last


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NASA’s JWST telescope spots fluorescing gas inflamed by surviving neutron star

When a nearby star exploded in 1987, it created the first supernova visible to the naked eye in 4 centuries and became one of the most intensely studied objects in space. Now, after more than 35 years of searching, researchers have finally discovered the cinder left behind. Using NASA’s new giant space telescope JWST, astronomers spotted glowing gas at the center of the blast that can only have been energized by something hot and compact inside it, they report this week in Science. They believe a neutron star, all that remains of the shattered star, is responsible.

For once the cliché is appropriate: “This is the smoking gun,” says astronomer Emanuele Greco of the Giuseppe S. Vaiana Astronomical Observatory of Palermo. “It’s a breakthrough in the sense of the information we will get about such an extreme and young object.”

Most supernovae go off when a large star, at least eight times the mass of the Sun, abruptly runs out of its fusion fuel. Without radiation pressure to hold up the star, the core collapses and the outer layers come crashing down. They bounce off the core and, getting a boost from a flash of tiny neutrino particles, blast most of the star’s mass into space. The core survives, and for the most massive stars, the result is a black hole. In others the collapse forms a solid ball of neutrons, packing a couple of solar masses into a city-size object. A teaspoon of the stuff would weigh 1 billion tons.