New Star Has Three Infant Planets Growing Around It

Scientists have been studying a distant exoplanet that is very young. The star is called HD 163296 and is about 330 light years from our solar system. The star is a scant 4 million years old, an infant by astronomical standards. The star is in the direction of the constellation Sagittarius.

Observations have been made using the Atacama Large Millimeter/submillimeter Array in Chile and have found that the star has a protoplanetary disk of dust and gas circling it. That disk has two dark gaps that astronomers believe have been carved out by newly forming planets. Evidence of a third planet has been found.

Scientists say that all three of these new planets are Jupiter-like gas giants and orbit at distances of 80 AU, 140 AU, and 260 AU. A single AU is the distance of the Earth from the Sun. While the ALMA data was used, the research teams also used a new strategy to determine if planets were forming in addition to the gaps in the dust cloud. That method involved looking at the motion of carbon monoxide gas.

Those gases move in a predictable way in protoplanetary disks unless met with gravitational obstacles. The team says that to create localized disturbances in the otherwise orderly motion of the gas, something "relatively massive" would have to be making the gravity, such as a planet.

Of the two teams working on the same project, the team led by Christophe Pinte from Monash University in Australia discovered the outermost planet in the system. A team led by Richard Teague from the University of Michigan used a similar method to find the other two planets.

SOURCE: Space.com