Figure 12-13

The Gum Nebula The Gum Nebula is the largest known supernova remnant. It spans 60° across the sky and is centered roughly on the southern constellation of Vela. The nearest portions of this expanding nebula are only 300 ly from Earth. The supernova explosion occurred about 11,000 years ago, and the remnant now has a diameter of about 2300 ly. Only the central regions of the nebula are shown here.