Blowing bubbles – Wolf-Rayet stars put on dramatic show

Wolf-Rayet stars are massive, high-energy suns near the end of their lives, pumping out thick, fast-moving stellar winds that can create vast bubbles in space as they ram into the cooler interstellar medium. Shockwaves heat up any gas in the region, occasionally to temperatures high enough to produce X-rays. But it is a relatively rare phenomenon, and only three such Wolf-Rayet stars have been found. This one, WR18, has extremely powerful winds, and once it exhausts its nuclear fuel it likely will explode in a supernova blast. This image was captured by the European Space Agency’s XMM-Newton space telescope. Hot X-ray emitting gas is shown in blue with yellow-green oxygen and red sulphur emissions are seen in optical wavelengths.

The fast-moving stellar wind shooting away from a massive Wolf-Rayet star collides with the interstellar medium, heating up and producing high-energy radiation that illuminates a vast bubble in space. Image: ESA/XMM-Newton; J. Toalá; D.Goldman