APOD 3.7 Vela Supernova Remnant in Visible Light

In the constellation of Vela, a star exploded about 11,000 years ago. The remenents of the supernova can be seen today. Spanning 100 light-years across, the picture is captured in visible light. The boundary of the shock wave, however, can be seen in x-ray. At the center of the supernova, the dead star, now a Pulsar, can be seen. It is as dense as nuclear matter and spins over 10x a second.