X rays from Supernova Remnant SN 1006 . ... Credit Copyright: NASA / CXC / P. Frank Winkler ( Middlebury College ) Explanation: What looks like a puff-ball is surely the remains of the brightest supernova in recorded human history. ... Now known as the SN 1006 supernova remnant , the debris cloud appears to be about 60 light-years across and is understood to represent the remains of a white dwarf star. ... The buildup in mass finally triggered a thermonuclear explosion that destroyed the dwarf star. ...