WASHINGTON, Oct 7: It’s the biggest thing found orbiting the sun since astronomers discovered Pluto in 1930, but please do not call it a planet. Call it Quaoar.

At half the size of Pluto, Quaoar — pronounced KWAH-o-ar — is a large celestial object, but not large enough to be a planet, one of its discoverers said in a telephone interview.

Quaoar’s discovery also calls Pluto’s planet status into question, said Mike Brown of the California Institute of Technology, who first detected the object on June 4. His findings were presented on Monday to the American Astronomical Society’s planetary science division meeting in Birmingham, Alabama.

Still, Quaoar acts a lot like a planet. Circling the Sun once every 288 years, Quaoar is located a billion miles (1.6 billion km) beyond Pluto, in an area loaded with icy orbiting objects called the Kuiper Belt.

The Kuiper Belt is where comets originate, and astronomers have long believed it harbors planet-shaped rocks like Quaoar. Over the last decade, more than 500 Kuiper Belt objects have been detected.

“In any realistic definition of a planet, you would have to say something like, a planet is significantly bigger than everything around it,” Brown said. “(Quaoar) is only 50 percent bigger than the next biggest Kuiper Belt object, to me it’s not massive enough.”

Quaoar’s existence confirms that large orbiting bodies can reside at the very fringes of our solar system, and could give new insights on the primordial materials that formed planets like Earth some five billion years ago.

PLUTO’S PLANETARY STATUS QUESTIONED: It also supports the theory that Pluto is not a planet at all, but rather a Kuiper Belt object. Pluto has a similarly long orbit — 248 years to make a complete trip around the sun — but is far more eccentric than Quaoar seems to be.