2011-03-03

Baby Planet


For the first time ever, scientists believe they've detected the birth of a new world around a distant sun-like star.

If confirmed, the discovery, using the European Southern Observatory's Very Large Telescope, would provide scientists with the earliest view yet of how short-lived discs of material around young stars clump together in the early stages of planetary formation.

Astronomers studying T Chamaeleontis (T Cha), a faint star 350 light-years from Earth in the southern constellation of Chamaeleon, detected a large gap in a disc of material around the star. They then found a small object in the disc which may be the cause of the gap.

The finding is detailed in two papers in the current edition of the Journal of Astronomy and Astrophysics.

Johan Olofsson from Germany's Max Planck Institute for Astronomy and lead author of one of the papers says the star was targeted because it's comparable to the sun, but aat just seven million years old it's still near the beginning of its life.

"Earlier studies had shown that T Cha was an excellent target for studying how planetary systems form, but this star is quite distant and the full power of the Very Large Telescope was needed to resolve very fine details and see what is going on in the dust disc," Olofsson says.

Scientists know planets form out of the discs of material around young stars, but theory says the transition from dust disc to planetary system is rapid and few objects are caught during this phase.

This is the first time a forming planet has been found in one of these transitional discs, although planets in more mature discs have been seen before.

Nuria Huelamo from the Centro de Astrobiologia, in Spain, and lead author of the second paper says the gap in the disc was the smoking gun: "We asked ourselves: could we be witnessing a companion digging a gap inside its protoplanetary disc?"

After careful analysis they found the clear signature of an object located within the gap in the dust disc, about one billion kilometers from the star. That's slightly further out than Jupiter lies from our sun.

This is the first detection of an object much smaller than a star within a gap in the planet-forming dust disc around a young star.

Baby Planet