Scientists have found further evidence that red dwarfs, once thought to be a bastion for habitability, may not be the oases of life we were looking for.
Using data from NASA’s Galaxy Evolution Explorer (GALEX) spacecraft, researchers found that red dwarfs undergo both large and small flares that could erode the atmospheres of nearby planets. They could also damage any life on the surface, or prevent it arising at all.
The research was led by Chase Million of Million Concepts in State College, Pennsylvania, and presented this week at the 230th meeting of the American Astronomical Society in Austin, Texas.
The team looked at 10 years of observations by GALEX, which monitors stars in the ultraviolet wavelength. Red dwarfs themselves are dim in ultraviolet (but strong in infrared), which allowed the researchers to see even small ultraviolet flaring events.
Looking at several hundred red dwarf stars, they saw dozens of flares. These ranged “from itty bitty baby flares that last a few seconds, to monster flares that make a star hundreds of times brighter for a few minutes,” Million said in a statement. All the flares were similar in power to those from our own Sun, but as the planets are much closer, they are subjected to more of their potentially damaging energy.
While only a few dozen were found, the team said they expected to find hundreds of thousands of flares in the GALEX data. That’s not a good thing – the more we find, the less promising red dwarfs become.