An artist's concept shows a family of six planets orbiting a star known as Kepler 11, which was discovered by the planet-hunting Kepler spacecraft. The six planets are packed in close to the star; all orbit at less than half of Earth's distance from the Sun. They were discovered as they crossed in front of the star (as three are doing in this illustration), blocking a tiny bit of the star's light. Kepler has discovered evidence of about 1,200 other worlds in other star systems, but most of them are awaiting confirmation. [NASA/Tim Pyle]
Until a few months ago, GSC 03144 was just another yellow-dwarf star -- one of billions in the Milky Way galaxy. It's the same size, mass, and temperature as the Sun, and perhaps a few billion years older.
Today, though, it's a stellar celebrity. It's home to one of the largest planetary systems yet discovered -- a family of six worlds. Only one other system beyond our own is known to have that many planets.
It also has a new name: Kepler 11 -- the 11th star for which the Kepler space telescope has discovered planets.
Kepler's goal is to find Earth-size worlds in Earth-like orbits around Sun-like stars. Such worlds are the most likely to be Earth-like, with conditions that are friendly for life.
It'll take another couple of years for Kepler to confirm such worlds. In the meantime, it's discovering lots of other planets. In February, mission scientists released a catalog of about 1200 possible worlds orbiting almost a thousand stars in the constellations Lyra and Cygnus.
The largest system in the bunch is Kepler 11. None of its planets is much like Earth, though. All six are less than half as far from their parent star as Earth is from the Sun, so they're too hot for liquid water -- a key ingredient for life as we know it. They're all a good bit bigger and heavier than Earth, too.
Even so, Kepler 11 shows that big planetary families are probably pretty common -- and some of them are likely to look like our own.
Script by Damond Benningfield, Copyright 2011
For more skywatching tips, astronomy news, and much more, read StarDate magazine.