Vela Supernova Remnant in Optical . ... Credit Copyright: Royal Observatory, Edinburgh , Anglo-Australian Observatory Explanation: About 11,000 years ago a star in the constellation of Vela exploded. This bright supernova may have been visible to the first human farmers . ... As gas flies away from the detonated star , it reacts with the interstellar medium , knocking away closely held electrons from even heavy elements . ... NASA Web Site Statements, Warnings, and Disclaimers . ...