When you think about stars twinkling overhead, you probably don’t associate them with a color. But the star Sirius shifts through every color of the rainbow. That effect is thanks to the same turbulence that bends starlight slightly and makes stars look like they’re twinkling in the first place. These air fluctuations bend different colors of light by different amounts, giving Sirius its multi-hued appearance.
The amateur U.K.-based astrophotographer Steve Brown managed to capture that stunning spectrum of light in his photo Scintillating Sirius, which was recently shortlisted for the Insight Astronomy Photographer of the Year awards. The image is a composite created by shooting video of the star deliberately out of focus, so the light of the star shows up on film like a lens glare. Brown then chose the most vibrant, unexpected colors and put them together into a composite image. The final shot has 782 twinkles of different colored light.
“I was surprised by the sheer number of different colors that came out,” Brown tells Co.Design in an email. “I was expecting to see mostly reds, greens, and blues, but it was amazing to see purples, pinks, oranges, and many other colors besides. Sirius truly lives up to its name as the ‘Rainbow Star!'”
One of Brown’s previous photographs, Rainbow Star, displays these color spots of light in a grid-like pattern; it won the Stars and Nebulae category of the Insight Astronomy Photographer of the Year in 2016. The kaleidoscopic new image, with Sirius’s light spots arranged in a circle, riffs on the same pattern and is even more stunning.
Brown says he deliberately broke several rules of astrophotography in order to get the effect: Besides the fact that the camera was out of focus, he also shot it when the star was low on the horizon–which usually makes for insufficient visibility. “In this case though it was just what I wanted, as light from the star was then passing through more atmosphere, which resulted in more twinkling and therefore a greater range of colors,” he says. You can see all the finalists for this year’s Astronomy Photographer of the Year competition here.