A red fireball with glowing spots against a pitch-black background: what appears to have been a picture taken by the James Webb Space Telescope turned out to be a slice of chorizo sausage.
The author of the picture, the French physicist and philosopher Etienne Klein, explained that he was joking.
On Wednesday, he apologized to everyone he misled.
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Klein posted the image to Twitter on Sunday, claiming it was of Proxima Centauri, the closest star to the sun.
While other Twitter users were still admiring the details in the picture, he shortly afterwards hinted at the real background of the shot - that it was actually a slice of the spicy Spanish sausage.
A day later he made it clear that it was a joke, then the French Huffington Post, among others, took up the cause.
With his post, he wanted to encourage caution against images that "appear meaningful on their own," Klein explained in another tweet.
He apologized to anyone who might have been offended by a scientist's "unoriginal" joke.
On Wednesday, the 64-year-old research director of the energy research institute CEA and producer of a French science program again posted a recording of the space telescope.
The image of the Cartwheel Galaxy is real this time, he assured.