Free Astronomy Magazine March-April 2022

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, spin- ning 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. [Danielle Futselaar, artsource.nl ]