The supernova remnant Puppis A is about 6,500 light years from Earth and was probably formed about 5,000 years ago in a star that exploded in a Type II supernova. The nebula is now about 100 light years in diameter and covers an area about 50 arc minutes. It is located in the constellation Puppis, the ShipΓÇÖs Stern, which is part of a larger group of stars known as Argo Navis.
This image is a composite of two taken in green and red wavelengths of visible light (about 5,000 and 6,500 angstroms respectively). The stars appear white, the knots of gas and dust green or red depending on their composition. The red areas, composed primarily of hydrogen gas, are moving at about 300 kilometers per second; the glow is
