Forming a Massive Star

Projected density distributions of dark matter (background and top panel) and gas (bottom three panels) components when the massive star forms. The stellar cradle is extremely asymmetrical as a wide, wedge-shaped structure (middle panel) due to the initial supersonic gas motions left over from the Big Bang. The circle in the right panel indicates the gravitationally unstable region with mass of 26,000 solar-masses. (Credit: Shingo Hirano)