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First Exoplanet Discovered Orbiting Two Stars
astroengine writes "For the first time, astronomers have discovered an exoplanet orbiting binary stars. Kepler-16b, a Saturn-sized world approximately 200 light-years away, orbits Kepler-16, two stars locked in a mutual dance. Although other exoplanets are known to exist in binary systems, they have only been known to be orbiting one star of the binary pair; Kepler-16b orbits both. No doubt Kepler-16b will excite memories of Tatooine, Luke Skywalker's homeworld, but the double sunset is where the similarities end. Kepler-16b would be anything but a desert world; it is the approximate size of Saturn, it is extremely cold, and its average density is that of water."
Tatooine? Would that thing not be much more like Solaris (the planet from the novel, not the OS), especially since it's density is that of water?
It's Saturn sized with density of water. It's a friggin' gas giant. It has no surface, unless you count the super-dense core that's probably hydrogen in a metallic state.
The world's burning. Moped Jesus spotted on I50. Details at 11.
Kepler is observing the dimming of the light of the star (basically a part of the star disc is shadowed by the planet), when the planet transits directly in the line of sight between Kepler/Earth and the star. Hence, you can get a cross-section area, and by assuming the planet to be reasonably spherical (a fair assumption), you get the volume.
Not sure if that's true or not, but if the planet had a dense, large, rocky core, it could hold on to a thick, massive atmosphere that's far less dense than liquid water, at least for much of its overall volume.
Saturn is a good example in our own solar system - it has an overall density less than the density of water. If you had a big enough bathtub, you could float Saturn in it.
It would leave a ring, though...