Stellar Neighborhood

via our geek friends at Astrobiology Magazine.

New survey of near-Sun stars raises the count to 384 stars in 249 systems within 33 light-years. Most of these are class M, or red dwarf stars, but interest in these is growing with the higher possibility that they could hold planets, perhaps even habitable ones. The increase in the number of stars in local neighborhood holds interesting implications for both the number of stars in the galazy, but also the universe, and may hold implications for the amount of mass it contains.

"If our neighborhood is representative of the galaxy, and the galaxy is representative of the universe, the new local density measurement may lead to a more precise calculation of the universe’s overall mass. More nearby stars also translates into the possibility of more nearby planets, and perhaps life. The possibility of habitable worlds around red dwarfs is still being debated, though. Because red dwarfs have such low heat output, only planets in close orbit would be warm enough to have liquid water on the surface."

The issue with being so close to a star is that the planet, like Earth's moon, might become tidal locked and only face one side of the planet to the Sun. This would cause that side to heat excessively and blow all chances of wate remaining, with the opposite side in a perpetual deep freeze. However, examples like Mercury, within our own system, lead many scientists to believe that most close orbiting planets would not be so locked, since they form from the same interstellar dust cloud that the star forms from. The really interesting thing about these stars holding planets is that they are the most common (up to 75% of all stars) type of star, so if planets commonly form around them (and we have examples), the number of exoplanets is likely to be much higher than previously thought. And with more planets, more chances for both habitable planets and life to evolve. Cool, unless they hold Klingons that want to eat us.