Thursday, April 21, 2011

Alien Worlds Could Circle Dying White Dwarf Stars

Scientists may be searching for Earth-like worlds around stars like our sun, but a new study suggests that the best places to look for planets that can support life may be the dying stars called white dwarfs.

Our sun — and indeed, more than 90 percent of all stars in our galaxy — will one day end up as white dwarfs, which are made up of their dim, fading cores. These cooling stars are typically about 40 percent to 90 percent of the mass of our sun but only about the same volume as Earth, and they are as common as sunlike stars. [The Strangest Alien Planets]

As cool as white dwarf stars might get, they would still be warm enough to possess so-called habitable zones — orbits where liquid water can exist on the surfaces of those worlds. These zones are considered prime habitats for life, as there is life virtually everywhere there is liquid water on Earth. (read more)