NASA detects planet dancing with 2 stars

From double sunrise to double sunset the show goes on, always changing.

Sometimes the orange sun rises first. Sometimes it is the red one, although they are never far apart in the sky and you can see them moving each other, casting double shadows across the firmament and periodically crossing right in front of each other.

Such is life, if it were possible, on the latest addition to the pantheon of weird planets now known to exist outside the bounds of our own solar system. It is the first planet, astronomers say, that has been definitely shown to be orbiting two stars at once, circling at a distance of some 65 million miles a pair of stars that are themselves circling each other much more closely. A team of astronomers using NASA's Kepler planet-hunting spacecraft announced the discovery Thursday in a paper published online in the journal Science, at a conference in Jackson Hole, Wyo., and in a news conference at NASA's Ames Research Laboratory in Mountain View, Calif., Kepler's headquarters.

The official name of the new planet is Kepler 16b, but astronomers are already referring to it informally as Tatooine, after the home planet of Luke and Anakin Skywalker, in the George Lucas "Star Wars" movies, which also had two suns.

"Reality has finally caught up with science fiction," said Alan P. Boss of the Carnegie Institution, a member of the research team.

Indeed, John Knoll, who is a visual effects supervisor at Industrial Light & Magic, which is part of Lucasfilm, and who worked on several of the "Star Wars" movies, joined the Ames news conference and showed a clip from the original movie.

"Again and again we see that the science is stranger and weirder than fiction," Knoll said. "The very existence of this discovery gives us cause to dream bigger."

While some double-star systems, of which there are billions in the galaxy, have been suspected to harbor planets, those smaller bodies have never been seen.

"This is a direct detection; it removes all doubt," said Dr. Laurance Doyle of the SETI Institute in Mountain View, who led the discovery team. "It will help those guys make their case."

Beyond the wow factor, astronomers said the discovery — as so many discoveries of so-called exoplanets have done — had thrown a wrench into another well-received theory of how planets can and cannot form.

"In other words," said Sara Seager, a planetary expert at the Massachusetts Institute of Technology who was not part of the discovery team, "people don't really know how to form this planet."