This artist's impression shows the dust trap in the system Oph-IRS 48. The dust trap provides a safe haven for the tiny rocks in the disc, allowing them to clump together and grow to sizes that allow them to survive on their own. (ESO/L. Calcada)
In a vast disc of gas and dust particles circling a young star, scientists have found evidence of a hypothesized, but never-before seen, dust trap that may solve the mystery of how planets form.We know planets that orbit stars are abundant throughout our galaxy, and likely throughout the universe as well, but until recently, scientists weren't exactly sure how those planets came to be.
The working theory is that they grew over time as tiny bits of dust collided and stuck together - eventually forming comets, rocky planets, and the cores of gaseous planets over millions of years.
But there is a problem with that theory: Once these tiny bits of dust grow to the size of pebbles or boulders, they are likely to either smash into each other and break apart, or spiral toward their central star where their growth is inhibited.
Theoretical astronomers had hypothesized that the flat discs of dust and gas that often surround young stars might occasionally contain dust traps - an area in the disc where the gas is more dense and can create a barrier that keeps more substantial bits of dust from falling toward the star.
Van Der Marel said this particular dust trap is not likely to create planets because of its location in the disc, but it could create comets as large as .6 miles across. Van Der Marel describes it as "comet factory."
This computer simulation shows how a vortex can form when a massive planet is interacting with a disc around a young star. It shows how the gas density evolves when there is a planet, with a mass ten times that of Jupiter, located at 20 times the Earth-Sun distance from the central star. A large-scale vortex is created at the outer edge of the gap, which can live for more than 1000 of the planet's orbits. This vortex can trap millimeter-sized particles over million years timescales and explain the high contrast structure observed with ALMA in the disc around Oph-IRS 48.
More information:http://www.eso.org/public/videos/eso1...
More information:http://www.eso.org/public/videos/eso1...
