https://phys.org/news/2018-07-solar-exoplanet-ability-stellar.html

The tool is the Alfvén Wave Solar Model (AWSoM) and has been used to simulate the behavior of the sun's corona. The researchers tweaked it for use in studying stars at the center of other star systems in the Milky Way galaxy—and by extension, the stellar winds that make their way to the planets in those star systems. In their study, the researchers focused on TRAPPIST-1, a star system that made headlines three years ago when scientists reported that it harbors seven Earth-sized planets, three of which reside in the Goldilocks Zone. Of those three, named e, f and g, the researchers were most interested in g, because prior work had suggested of the three, it holds the most promise for hosting life. One test of its suitability would be checking to see if the planet would be able to withstand the stellar winds. We here on Earth are protected from solar winds by both a magnetic field and our atmosphere.

To predict the impact of the stellar winds on g, the researchers added influences to the AWSoM, such as star age (a factor in heat production) and then allowed programmed it to simulate stellar wind. The researchers found that life did appear possible, so long as it was at least 125 miles below its ionosphere—at points below that, the atmosphere could conceivably provide enough protection to sustain life.

                                                            
                                    
                                    Explore further: