Steve Schulze

When a massive star runs out of fuel, it sheds its hydrogen envelope and explodes, like a final, desperate exhale. That’s exactly the kind of supernova (type Ib) astronomers observed. 62 days after the blast, in the cooling debris, they caught a faint infrared glow: it turned out to be the signature of carbon monoxide (CO).

A distant lamp shines through uneven glass. The glass bends the rays, and instead of one flame on the wall, several appear — some brighter, some fainter. In much the same way, a massive galaxy bends the light of an exploded star. There was one explosion, but the images show four glowing points.

A match flares from both ends. First the head ignites, and a moment later the flame engulfs the wooden stick. Something similar may happen in some Type Ia supernovae — except the match is a white dwarf (a star the size of Earth), and the flame is a thermonuclear explosion.