Cosmic newborns: Astronomers find the stuff of baby planets

Four free-floating objects carrying the raw materials that could turn them into large planets have been discovered by a team of Canadian-led astronomers.

Like young stars, these objects are swimming in discs of cosmic dust and gas, which the astronomers say are the basic ingredients for the formation of planets.

But instead of orbiting stars, as planets do, these "infant" objects, informally called planemos, float freely through space and areabout the size ofgiant Jupiter, though still roughly 100 times smaller than our sun.

"Our findings, combined with previous work, suggest similar infancies for our sun and objects that are some hundred times less massive", said Valentin Ivanov of European Southern Observatory, a co-author of the study.

"Now that we know of these planetary mass objects with their own little infant planetary systems, the definition of the word 'planet' has blurred even more," added the study's lead author, Ray Jayawardhana, a professor of astronomy and astrophysics at the University of Toronto.

Giant toddlers

Jayawardhana and his team detected four planemos just a few million years old in a star-forming region about 450 light-years from Earth.

A light-year is about 10 trillion kilometres, the distance light travels in a year.

All four objectsresemble a young Jupiter withdiscs of dust orbiting them, the team said, based on their observations from theEuropean Southern Observatory telescopes.

A second study by an American research team showed another planemo object surrounded by a disc interacting with a brown dwarf, or failed star, just 170 light-years away from Earth.

The two objects revolve around each other.

The discoveries aren't surprising given that Jupiter must have also been born with its own disk, Jayawardhana said.

The findings were presented this week at theAmerican Astronomical Society meeting in Calgary.