The blue gas clouds in this image are from the remnants of the Vela Supernova which was created by a star that exploded thousands of years ago. One sees NGC 2736, or the Pencil Nebula glow brightly in the frame. The nebula's shape suggests that it is part of a supernova shock wave that has encountered a region of dense gas and it is this interaction that causes the nebula to glow and form ripples. The nebula's linear shape and bright filaments earned it its name… The Pencil nebula.