Narrator (April Hobart, CXC): G299.2-2.9 is an intriguing supernova remnant found about 16,000 light years away in the Milky Way galaxy. Here we see the remnant in X-rays from Chandra overlaid on infrared data from the Two-Micron All-Sky Survey. Astronomers have gathered evidence that shows this remnant is the aftermath of what is called a Type Ia supernova. Type Ias happen when a white dwarf grows too massive and violently explodes. Astronomers want to understand the exact details of how Type Ias explode because they use them to measure the accelerated expansion of the universe and study dark energy. Because it is older than most Type Ias found so far, G299.2-2.9 provides astronomers with an excellent opportunity to study how these important objects evolve over time.
Revised: October 13, 2011