Photo: An image of the Tarantula Nebula in the Large Magellanic Cloud, taken with the ESO Schmidt Telescope. Supernova 1987A is visible as the very bright star in the upper middle. At the time this image was taken, the supernova was visible with the unaided eye | Credit ESO
February 23, 1987: Supernova 1987A explodes
Supernova 1987A (abbreviated to SN 1987A) was a type II1 supernova located in the Large Magellanic Cloud. SN 1987A was thought to be the result of a neutron star collapsing and exploding approximately 51.4 kiloparsecs (168,000 light-years) from Earth, a notion that was confirmed with northern Chile’s ALMA telescope in 2019.
The light from the explosion reached Earth on February 23, 1987, allowing astronomers to study SN 1987A in more detail than any supernova had been studied before. Before this, Kepler’s supernova (aka SN 1604), a type Ia2 supernova, was the only event of its kind to be unquestioningly observed from Earth by the unaided eye.
1 A type of supernova that results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, but no more than 40-50 times, the mass of the Sun for this type of explosion to occur.
2 A type of supernova that occurs in binary star systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white dwarf.