Water-Fountains---binary-star-system-16-9--full-res

A pair of stars at the start of a common envelope phase. In this artist's impression, we get a view from very close to a binary system in which two stars have just started to share the same atmosphere. The bigger star, a red giant star, has provided a huge, cool atmosphere that only just holds together. The smaller star orbits ever faster around the stars' center of mass, spinning on its axis and interacting dramatically with its new surroundings. The interaction creates powerful jets that throw out gas from its poles and a slower-moving ring of material at its equator. Credit: Danielle Futselaar, artsource.nl