This supernova dominated our skies for weeks, a thousand years ago. It was brighter than Venus and visible during the day, and observers documented it in China, Japan, Europe and the Arab world. We now know that the brightest supernova on record, SN 1006c, was caused by a white dwarf star that gained mass from a companion star until it gorged itself and exploded. Click through for some more mind-blowing images of SN1006c, including some super-colorful X-ray images.