High-power flares can destroy atmospheres from red dwarf planets.

"Artist rendition of DG CVn, a binary star system made up of two red dwarf stars. Illustration shows it unleashing powerful flares that could impact planet habitability. Credit: NASA" (ScitechDaily, When Stars Attack: High-Energy UV From Stellar Flares Could Threaten Life)

Red dwarfs are the most common stars in the Milky Way. Those red stars have solar systems, and sometimes people, like me, are introduced that those planets can host life. The problem is that planets in red dwarf's habitable zones are locked. But, the atmosphere stabilizes temperature.

Sometimes red dwarfs send extraordinarily strong UV flares. And those flares can wipe out the Red Dwarf's planet's atmosphere.  The reason for those flares can be in the red dwarf's internal power production. Otherwise, those red dwarfs are very cold stars. Their surface temperature is about the same as acetylene flame. 

"Illustration of exoplanet Kepler-1649c orbiting around its host red dwarf star. Credit: NASA/Ames Research Center/Daniel Rutter" (ScitechDaily, When Stars Attack: High-Energy UV From Stellar Flares Could Threaten Life)

But that means that those eruptions must happen regularly. Sometimes the reason for the sudden flare eruptions is introduced GRB, XRB, or FRB (Gamma, X-ray, or fast radio bursts). If those high-energy busts hit a red dwarf, they can raise its temperature to a higher level than normal fusion makes. That kind of bursts or "superflares" can be devastating. The FRB that hits red dwarf can increase its fusion and energy production. 

But are lifeforms possible on red dwarf planets? There is the possibility that some kind of fish-looking organisms can live underwater on planets that are so-called water worlds. An ocean that is hundreds or even thousands of kilometers deep can offer protection against those radiation bursts. Or the life on those planets can be very local and it might live in some deep valleys. The lifeforms on those planets would be primitive. But as we know red dwarfs are hostile to lifeforms. 

"UV radiation from stellar flares can erode planetary atmospheres. Credit: University of Hawaii at Manoa"(ScitechDaily, When Stars Attack: High-Energy UV From Stellar Flares Could Threaten Life)

Sometimes is introduced that red dwarfs can be friendly stars for civilizations that are from some other solar systems. The red dwarfs can be parts of the binary or multiple star systems.  As an example: Proxima Centauri is a member of the Alpha Centauri system. If the distance from the center star to the red dwarf planet system is like Pluto's distance to Earth, the hypothetical civilization can travel that journey more easily than humans. 

We have one problem. We have no object where to travel. The civilization sees real planets. And, they can use things like solar sails and nuclear chemical rockets to travel so close solar system. So what our technology would look like if the Nemesis star of stories existed? And there would be a planet in a habitable zone. Those things are good to think.