Tuesday, April 8, 2008

Youngest planet

An embryonic planets outside our solar system discovered a system could be less than 2000 years old, say astronomers.

The ball of dust and gas that is in the process of transforming into a giant Jupiter, it was found around the star Tau HL, by a British team.

Research leader Dr. Jane Greaves, said the planet `s growth in May were kickstarted when another young stars to the system 1600 years.

Details were presented at the UK National Astronomy Meeting in Belfast.

The scientists studied a disk of gas and rocky particles to HL Tau, which is 520 light years away in the constellation Taurus and thought to less than 100000 years old.

The disc is unusually massive and bright, making it an excellent place to search for evidence of planets in the process of formation.

The researchers say their image belongs to a proto-planetary still embedded in his birth.

Dr. Greaves of the University of St. Andrews, Scotland, said the discovery of a planet around the formation of such a young star was a big surprise.

"It was not really what we were looking for. And we were surprised when we found it," she said BBC News.

"The next planet confirmed youngest is 10 million years old."

When the proto-Earth is assumed that the same age as the star it orbits, which would be several hundred times less than the previous record holder.

`` Record holder The growth of the planet But it is an interesting suggestion that the gas giant, which is about 14 times as big as our Jupiter, could even younger.

With the Very Large Array (VLA) radio telescope in the USA, the researchers studied the system on emission wavelengths specially selected to the search for rocky particles approximately the size of pebbles. The presence of these pebbles is a clue that rocky material gradually clump together to form planets.

In the United Kingdom, researchers used the Merlin radio telescopes at Jodrell Bank in Cheshire study on the same system at longer wavelengths. This allowed them to confirm the emissions were from rocks, and not from other sources such as hot gas.

In addition to the detection of super-large dust in the disc to HL Tau, she was also an extra bright "clump" of the material.

This confirms a so-called "nebulosity" seen a few years earlier in the same position, by a team led by Dr. Jack Welch of the Berkeley-Illinois-Maryland Array, USA.

Formation Theories

Dr. Ken Rice, from the Institute for Astronomy in Edinburgh, said the discovery throw new light on theories of planet formation.

Following a model that planets form from the bottom up. Under this scenario, particles of rocky material collide and "stick" to one another, a larger object.

But he says that the proto-Earth and HL Tau formed relatively quickly, if a region of the disc collapsed into a self-contained. This can occur because of the gravitational instability in the disk.

Dr. Rice said his computer simulations were like a good fit for the observation that it seemed, could the mechanism really in the nature.

Surprisingly other young star in the same region XZ Tau May, a narrow pass of HL Tau about 1600 years ago.

Although not required for planetary formation, it is possible that this summary surprised the disc, making it unstable. This would be a very recent event in astronomical terms.

"It` s possible, it was a "yank" on one side of the disc to HL Tau, making it unstable, and this was a "trigger" for the planet, "said Dr. Greaves.

"If the planets formed in the last 1600 years, that would be incredibly young."

The Royal Astronomical Society's National Astronomy Meeting 2008 continues through Friday at Queen's University in Belfast.