Este fue
tu cielo.

Nebula Nova Cygni Turns On

In 1992, a white dwarf star in Cygnus exploded, an event called Nova Cygni. Light from that nova expanded into space, illuminating a pre-existing cloud of hydrogen gas. The small red ball just above center is the only gas actually expelled by the nova. The rest is a cosmic light show, a nebula that wasn't there until the light from the nova turned it on.