Free Republic

Astronomers have finally found a planet around the closest single star to the Sun — and there are probably more worlds in this system. The find settles years of controversy.Some stars seem like perfect targets for exoplanet hunters. Barnard's star is certainly one of them: At only six light-years from the Sun in the direction of Ophiuchus, it is the nearest single star and the second-nearest star system after Alpha Centauri. It's so close that you can detect its movement across the sky in photographs taken just a few years apart.Claims of planetary companions to Barnard's star have been made...

The red dwarf star itself emits only about 0.4% of our sun's radiance, so the planet receives about 2% of the intensity that Earth receives from its sun. This is because Barnard's star is in the class of M dwarf stars, cooler and less massive than our sun. It's also an old star that predates our own solar system. The planet is about the same orbital distance from its star as Mercury is from our sun, making a full pass around the star every 233 days. This places it in the "snow line" of the star, where it's cold enough...