The story of Pickering’s Triangle begins 10,000 to 20,000 years ago, when a massive star, 2400 light-years from Earth, exploded as a supernova. The blast tore the star apart, sending shockwaves racing outward at 600,000 kilometres per hour, ploughing into the surrounding interstellar medium.

Pickering’s Triangle is a region where these shockwaves encounter clumps of gas at slightly different densities and speeds. This impact creates the knots and filaments visible in my image, stretching across about 40 light-years. The gas glows because it’s heated to millions of degrees and ionised by the energy of the expanding shockwave. Different elements produce different colours: during image processing I mapped hydrogen to orange and oxygen to light blue.

Below are a selection of close-crops highlighting shock fronts, where the supernova’s expanding shell impacts gas and dust, creating rippling effects. I think that each one looks like an abstract painting. Use the slider function for inverted views, which can help make the finer structures easier to see.