Wolf–Rayet stars are high mass, evolved suns that have shed their outer layers and now blaze fiercely as their exposed cores hurl gas into space. WR 134 has a scorching surface temperature of over 60,000 degrees, and its stellar winds blast outward at 1700 kilometres per second.

It’s those winds that are sculpting the bubble around WR 134. Most of the surrounding nebulosity is hydrogen (which I’ve coloured as orange). WR 134’s shell is mainly oxygen (with electrons stripped away by the star’s radiation). In my image this oxygen is blue. This shell is actually a vast shock front where the star’s outflow slams into surrounding gas and dust, heating it to tens of thousands of degrees.

To make the shell easier to see, I made an image with all the other stars removed, leaving just WR 134 and its surroundings. Use the slider to see an inverted view, which I think makes some of the fainter structures stand out more. Amazing to think this is visible using amateur equipment from the centre of a city!

That shell is enormous — about six light-years across. To put that in perspective, you could fit our Solar System (which for simplicity I’m taking as the Sun to Pluto) across it 10,000 times.

WR 134 is in the end stages of its existence. It probably has in the region of a few hundred thousand years left (not long from an astronomical perspective!) until it explodes as a supernova and leaves behind either a neutron star or a black hole.