U.S. astronomers witness new planets being born
Friday, February 27th, 2004Astronomers are happy because they are now able to prove one of their theories on the formation of planets. A 12 million year old star, 33 light years away, called, AU Microscopium or AU Mic, is in the process of creating some planets.
They have seen evidence of a disk of dust orbiting the star — a disk like the one our own solar system is believed to have formed from.
And within the disk is a clear swathe, which suggests a planet has started to form and has scooped up some of the dust in the process.
The star, called AU Microscopium or AU Mic, is dimmer and redder than our own Sun, so any planets orbiting it are likely to be cold.
“The dust missing from the inner regions of AU Mic is the telltale sign of an orbiting planet,” Michael Liu of the University of Hawaii, who helped lead the team, said in a statement.
“The planet sweeps away any dust in the inner regions, keeping the dust in the outer region at bay.”
Liu and colleagues used telescopes on Hawaii’s tall Mauna Kea peak to find the young planetary system. They were pleased to find one so close.
A light-year is the distance light travels in a year, and 33 light-years is close enough to let scientists try to see the star better using the Hubble Space Telescope (news - web sites) or ground-based telescopes.
“We know that extrasolar planets are common, but understanding how they form is an outstanding question. Because AU Mic is so near to Earth, it provides us a special opportunity to examine planet formation in great detail,” Liu said.
Writing in the online Science Express version of the journal Science, Liu’s team said AU Mic is extremely young — just about 12 million years old compared to our own Sun’s age of 4.6 billion years.
What they see fits in with theories about how stars and planets form — with the star forming first, and a circling ring of dust gradually accumulating into orbiting planets.
The final planets probably won’t be completely formed for a few million years. I think that would qualify as one of the longest known labors.




