Scientists are still learning about a cosmic "string of pearls," a unique celestial relic left by a supernova explosion that humanity witnessed around 850 years ago.
That is thanks to the most detailed observation of the dandelion-shaped chains of gas and supernova debris that comprise Pa 30, the only supernova remnant of its type observed in the Milky Way. What makes Pa 30 even more unique is that it has a rare "zombie star" at its heart.
Supernovas like the one that created Pa 30 are called Type Ia supernovas; they happen when a dead star called a white dwarf overfeeds on a companion star like a cosmic vampire. This overfeeding triggers a runaway nuclear explosion that usually destroys the white dwarf. But on rare occasions, the supernova doesn't completely destroy the star, and a shattered stellar body re...
