Supernova 1987A was the closest observed supernova since Kepler's Supernova in 1604, making it easily visible to the naked eye.

Neutrinos escape the collapsing core immediately, while the explosive shockwave takes hours to reach the star's surface to produce visible light.

Prior to 1987A, stellar evolution models predicted that only massive red supergiants, not blue supergiants, could explode as supernovae.

The collision of the supernova shockwave with a pre-existing ring of gas created bright hotspots that look almost exactly like a glowing string of pearls.