№ 13 Supernova RemnantDORADO2026.05.01

SN 1987A — Wikimedia Commonssource · public domain or CC — see source page for exact terms

Supernova 1987A

Distance

about 51.4 kiloparsecs (168,000 light-years)

Size

unknown

Discovered

1987 (designated SN 1987A; first supernova discovered that year)

Magnitude

+3 (about), at peak in May 1987

Light and neutrinos from this explosion reached Earth on February 23, 1987. At its peak in May 1987 it shone at about apparent magnitude 3—brighter than Alpha Doradus, the brightest star in Dorado.

Briefing

Supernova 1987A is a Type II supernova event in the constellation Dorado, located in the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way. It occurred approximately 51.4 kiloparsecs (168,000 light-years) from Earth and was the closest observed supernova since Kepler’s Supernova in 1604.

How we know

SN 1987A became the first supernova that modern astronomers were able to study in great detail, and those observations provided insight into core-collapse supernovae. Its long-lasting visible glow was tied directly to radioactivity by detecting predicted gamma-ray line radiation from two abundant radioactive nuclei—an observation that confirmed the radioactive source of the energy behind supernova visible-light emission after the explosion. In 2019, indirect evidence for a collapsed neutron star within its remnants was reported using the Atacama Large Millimeter Array.

From about 168,000 light-years away, the event still became a naked-eye object, peaking at about magnitude 3.