SN 1006: History's Brightest Supernova.

Suddenly, in the year 1006 AD, a new star appeared in the sky. Over the course of just a few days, the rogue star became brighter than the planet Venus . The star, likely the talk of everyone who could see it, was recorded by people who lived in areas now known as China , Egypt , Iraq , Italy , Japan , and Switzerland . The celestial newcomer, now known to be a supernova , took months to fade. Modern observations have been used to measure the speed of the still-expanding shock wave , allowing a better estimate of its distance and hence a better estimate of the true brightness of the supernova . It turns out SN 1006 likely achieved an apparent visual magnitude of -7.5, making it the brightest supernova on record. The shock wave was imaged in 1998 from CTIO (left panel), and then subtracted from a similar image taken in 1986 (right panel), highlighting the relative expansion.