Astronomy Picture of the Day

Explanation: Bright and beautiful spiral galaxy M83 lies a mere twelve million light-years from Earth, toward the headstrong constellation Hydra. Sweeping spiral arms, prominent in visible light images, lend this galaxy its popular moniker -- the Southern Pinwheel. In fact, the spiral arms are still apparent in this Chandra Observatory false-colour x-ray image of M83, traced by diffuse, hot, x-ray emitting gas. But more striking in the x-ray image is the galaxy's bright central region. The central emission likely represents even hotter gas created by a sudden burst of massive star formation. Point-like neutron star and black hole x-ray sources, final stages in the life cycles of massive stars, also show a concentration near the centre of M83 and offer further evidence for a burst of star formation at this galaxy's core. Light from this burst of star formation would have first reached Earth some 20 million years ago.