IIRC, human visitors to the bottle city of Kandor in Superman’s Fortress of Solitude could get around okay as long as they had some nifty gizmo compensating for the difference in gravity. The (simulated) red sun rays didn’t affect them at all.

–Phil
(Doing what he can to promote better understanding of Kryptonian science.)

Really, though, the great advent of “C” isn’t that they found a world that might contain life, it’s that they found an earthlike world in a habitable band of the star. This isn’t a Super Jupiter within an AU of the star.

This means, to my mind, not only is the technology to find MORE earth-like worlds there, but that, if they could find one so “easily” (after looking at a mere hundred stars), then there’s probably quite a few of these out there. If there’s quite a few of them, it’s quite likely we will find a planet with undoubtadly the right mix for life.

That’s what makes this a resounding discovery, to my mind.

In any case, there’s two conditions for being considered “Earth-like”, first that the planet orbits in a temperature band (dependent on the energy output of the star) over which liquid water can in theory exist on the surface and has a mass similar to that of Earth. As I believe I’ve mentioned before, Mars and Venus are both “Earth-like” planets on opposite fringes of the temperature zone with Earth in the middle.

The problem with red dwarf stars is that they still have significant stellar flares. And that can be quite lethal at the distances that one needs to be to keep warm.

UV radiation isn’t a significant problem. The spectrum of a “black body” drops rapidly from the peak (Gliese 581 has a temperature of 3,478 K while the Sun has a temperature of 5785 K). Given that for the planet to be “Earth-like” in temperature, it must be receiving similar amounts of total energy from the star. Hence, it probably receives less UV than we do from the Sun. It also probably receives less visible light (usable for photosynthesis) as well.

So the background radiation environment is probably better, but the stellar flares probably make the environment extremely hazardous to most Earth life (except for the organisms that can achieve cryptobiosis and are famous for being able to survive huge amounts of radiation and other things that cause genetic damage).

Of course that balmy 32-104 would not be accurate if the planet is in tidal locked.

Perhaps. Having to get that close for heat radiation may mean to harmful UV radiation is equally dim. Or not.

We really do need an astronomer to enlighten us on this.