
Nearly a millennium ago sky-watchers recorded a new star so bright it was visible in daylight for weeks, and Hubble has now traced how far its remnant, the Crab Nebula, has expanded since — a thousand-year-old explosion still visibly unfolding
In July 1054, court astronomers in China recorded a new "guest star" near Tianguan, the star we now call Zeta Tauri.














