Vela Supernova Remnant in Visible Light

The explosion is over but the consequences continue. About eleven thousand
years ago a star in the constellation of Vela could be seen to explode,
creating a strange point of light briefly visible to humans living near
the beginning of recorded history. The outer layers of the star crashed
into the interstellar medium, driving a shock wave that is still visible
today. A roughly spherical, expanding shock wave is visible in X-rays. The
above image captures much of that filamentary and gigantic shock in visible
light, spanning almost 100 light years and appearing twenty times the diameter
of the full moon. As gas flies away from the detonated star, it decays and reacts
with the interstellar medium, producing light in many different colors and energy
bands. Remaining at the center of the Vela Supernova Remnant is a pulsar, a star as
dense as nuclear matter that completely rotates more than ten times in a single second.