"Red Dwarfs May Be Safe Havens For Life"
Space News, Discovery News (July 4, 2010)
"It's been 15 years since astronomers first discovered a planet beyond the solar system orbiting a normal star. We've found lots of unusual exoplanets since then, but nothing where we think life could exist.
"In two to three years NASA's Kepler space telescope will provide the statistical bedrock for estimating the number of Earth clones in the galaxy...."
"...The planet will orbit a nearby red dwarf star found in surveys taken within 100 light-years of Earth. Why? Because red dwarfs are much more numerous than sun-like stars and so provide many more targets. Because red dwarfs are dim, planets orbiting them will not be as swamped by starlight and so their light is easier to measure...."
Some of this I'd read before: like a planet that's close enough to a red dwarf to be habitable (by us) would likely be tidally locked, with one side always facing the star. Some I hadn't. Red dwarf stars go through a long period in which they have flares: big ones. Radiation from those flares would be really, really hard on living things on any planet close enough to have liquid water.
Unless there was a super-strength ozone layer. Which, maybe, there would be. Universidad Nacional Autónoma de México (UNAM)'s astrobiologist Antigona Segura ran numbers from a known red dwarf flare - and demonstrated that the UV radiation would strengthen the ozone layer of an Earth-like planet - assuming that one was there.
All of which is quite theoretical, until we find a roughly Earth-size planet in a stable orbit at the right distance from a star.
Which, at the rate planets are being found these days, may not be that far off.
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