Los Angeles ? Astronomers announced Friday that they have discovered a new planet larger than Pluto in orbit around the sun, likely renewing debate over what exactly is a planet and whether Pluto should keep its status.

The planet – the farthest-known object in the solar system – is currently 9 billion miles away from the sun, or about three times Pluto’s current distance from the sun.

“This is the first object to be confirmed to be larger than Pluto in the outer solar system,” Michael Brown, a planetary scientist at the California Institute of Technology, said in a telephone briefing Friday.

Brown labeled the object as a 10th planet, but there are scientists who dispute the classification of Pluto as a planet.

Astronomers do not know the new planet’s exact size, but its brightness shows that it is at least as large as Pluto and could be up to 1 1/2 times bigger. The research was funded by NASA.

This artist's conception, released by NASA, shows the planet catalogued as 2003UB313 at the lonely outer fringes of our solar system. Our sun can be seen in the distance.

Brown has submitted a name for the new planet to the International Astronomical Union, which has yet to act on the proposal, but he did not release the proposed name Friday.

The briefing was hastily arranged after Brown received word that a secure Web site containing the discovery was hacked and the hacker threatened to release the information.

Brown and colleagues Chad Trujillo of the Gemini Observatory and David Rabinowitz of Yale University first photographed the object in 2003 using a 48-inch telescope at the Palomar Observatory.

But it was so far away that its motion was not detected until data was analyzed again this past January. It will take at least six months before astronomers can determine its exact size.

It has taken scientists this long to find the planet because its orbit is at an angle compared to the orbits of most planets. The new planet is rocky and icy, similar to Pluto, Brown said.