Vela supernova remnant

Around twenty thousand years ago a star in the Alpha Quadrant exploded; while the explosion is over the consequences continue. The outer layers of the star crashed into the interstellar medium, driving a shock wave that is still visible today. 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.

Structure

A roughly spherical, expanding shock wave is visible in X-rays. In the optical photograph to the right, the upper left corner of the spherical blast wave is shown in detail. As gas flies away from the detonated star, it reacts with the interstellar medium, knocking away closely held electrons from even heavy elements. When the electrons recombine with these atoms, light in many different colors and energy bands is produced.