An 850-year-old supernova turned out to be strung with pearls

In August 1181, sky-watchers in Japan, China, and the Arab world all recorded a brilliant new star that lingered for 185 days. Nearly 850 years later, astronomers have now seen its leftover — a ghostly firework of gas called Pa 30, the only known remnant of its rare kind in the Milky Way — in unprecedented detail. Using the Gemini North telescope in Hawaii, a team led by Ilaria Caiazzo and Tim Cunningham discovered that what looked like smooth streaks are actually chains of glowing knots strung like pearls — each one wide enough to hold our solar system's planets about ten times over. At the center sits a surviving 'zombie star,' the remnant of an explosion that couldn't quite finish the job. The findings, published in The Astrophysical Journal, turn a medieval mystery into one of the most beautiful images of the year.