In 1987, a big star exploded far away in space. This kind of explosion is called a supernova. Before people saw its light, a machine deep under the ground in Gifu, Japan, caught tiny particles from the star. These particles are called neutrinos.

The machine, Kamiokande, found 11 of them in about 13 seconds. This discovery later helped a Japanese scientist win a Nobel Prize.

In February 1987, a massive star in the Large Magellanic Cloud, a galaxy 160,000 light-years away, exploded as a supernova. When such a star runs out of fuel, its core suddenly collapses and releases huge numbers of neutrinos, tiny particles that pass through almost everything. Because neutrinos escape the star quickly while light is delayed by the star's outer gas, the neutrinos reached Earth about two hours before the light was spotted.

Kamiokande, a huge water tank 1,000 meters underground in Gifu, Japan, detected 11 neutrinos in about 13 seconds, and a US detector caught 8 at the same time. This was the first detection of neutrinos from beyond the Sun, and it led to a Nobel Prize in 2002.

When Supernova 1987A erupted in the Large Magellanic Cloud, about 160,000 light-years away, the first signal to reach Earth was not light. As the core of a massive star collapses, it releases an enormous burst of neutrinos, particles that interact so weakly with matter that they stream straight out, whereas light must work its way through the star's outer layers. According to NASA, the neutrinos therefore arrived about two hours before the light was detected.

In a 3,000-ton water tank 1,000 meters underground in Gifu, the Kamiokande team led by Masatoshi Koshiba recorded 11 neutrinos within about 13 seconds, and the American IMB detector simultaneously registered 8, confirming the signal's origin. Though few, these events provided the first direct evidence of core collapse, the first neutrinos detected from beyond the Sun, and the birth of neutrino astronomy; Koshiba received the 2002 Nobel Prize in Physics. But the expected neutron star stayed hidden behind dust for decades. Only in 2024 did the James Webb Space Telescope detect highly ionized argon near the center, and all the likely scenarios the researchers found involved a newborn neutron star.