This cosmic puff ball is the remains of the brightest supernova in recorded history. In AD 1006, a supernova lit up the nighttime skies and was seen by observers China, Egypt, Iraq, Italy, Japan, and Switzerland. This image was assembled from data at three different wavelength of X-rays taken from orbit by Chandra X-ray Observatory. The debris cloud from what is now called the SN 1006 supernova remnant is about 60 light-years across. It’s the remains of a white dwarf star that was part of a binary star system. The white dwarf gradually captured ate its companion star, and the increase in mass caused a thermonuclear explosion. Because the supernova remnant is about 7,000 light-years away, that explosion actually happened 7,000 years before the light reached Earth in 1006, or in roughly 6000 BC.
Image Credit: NASA