Artist’s impression of a red dwarf star like Proxima b
Illustration: NRAO/AUI/NSF; D. Berry (NRAO)

Scientists have discovered a flare off of the sun’s closest stellar neighbor, Proxima Centauri. Many are reporting that it could spell trouble for any hope for life on its exoplanet, Proxima b—but it might also kill off a presumed set of other planets around the star.

Last fall, lots of folks, including me, reported on evidence of dust rings around Proxima Centuari. These potential rings would imply that the star could have an elaborate planetary system alongside its confirmed exoplanet, Proxima b. But a new analysis of the same dataset calls those past results into question.

“While there could be other planets, we don’t have evidence of it yet,” study author Alycia Weinberger from the Carnegie Institute for Science told Gizmodo. “There’s the one planet detected a couple of years ago but no evidence for the disk.”

The researchers used data from the Atacama Large Millimeter/submillimeter Array (ALMA), dozens of radio dishes in the Chilean desert that can image radio-wavelength light emissions to precise detail. But rather than just average all of the data out, they watched how it changed over time. This new analysis implied that the star actually released a 1-minute-long flare, a thousand times brighter than the star’s usual shine—perhaps 10 times brighter than the most powerful solar flares from our own sun on record, said Weinberger. Their results have been accepted to The Astrophysical Journal Letters.

This observation over time meant that the single flare may account for what appeared to be rings of dust, she said—It’s kind of like getting three zeroes and a hundred on three tests. Saying that your average was 25% isn’t telling the whole story.


For what it’s worth, Guillem Anglada, who worked on the paper that found evidence for dust rings, agreed with the new evidence suggesting the flare. “It’s also present in our analysis of the data which was performed in a slightly different way,” he told Gizmodo. But he doesn’t think it kills the dust ring theory. “It decreases the calculation of the amount of dust, probably by a factor of two or even three, but it’s still consistent with the presence of rings of dust around Proxima Centauri.”

He told Gizmodo that his team is double checking everything and preparing a paper with another analysis of the data.

Sure, the new paper may also call into question Proxima b’s habitability, but that’s never been a given. Even when scientists first discovered the exoplanet, then-Gizmodo science writer Jennifer Ouellette wrote that “because Proxima Centauri is a fairly active star, Proxima b suffers x-ray fluxes approximately 400 times greater than what we experience here on Earth, and this could cause any atmosphere to blow away.”


But not all hope is lost for potential life on Proxima b. “People need to do some serious work to look at whether an atmosphere or ocean could survive, given the events from the star,” said Weinberger. If an ocean was there it could potentially protect life, for example. But there’s certainly more study required before determining whether the planet is habitable or not.

While lots of other folks might be talking about life on Proxima b, this new study is probably more important for what it means to the potential rings of dust around the parent star. Without these rings, there might not be evidence for planets other than Proxima b around our sun’s closest stellar neighbor.


This post has been updated.