In a discovery, an global team of astronomers has used a new technique to discover three infant planets which are around the newborn star, and they are incredible in finding that they are affirming long-held assumptions for the planet formation. By studying the motion of the CO gas and the patterns it follows, the astronomers stumbled upon three disturbances in the flow of particles, which could only indicate the presence of planets.
They studied the spread of carbon monoxide within the disc, observing the wavelengths of light emitted from molecules of the gas, which revealed how it was moving about.
Instead of finding for the planet itself, they found for a subordinate way looking for how a planet affects its environment.
Analyzing data from observations made from the Atacama Large Millimeter/submillimeter Array (ALMA) in northern Chile, the teams uncovered three distinct anomalies in the flow of gas on the disk surrounding the star HD 163296. It's 330 light-years from Earth in the direction of the constellation Sagittarius.
"This method will provide essential evidence to help interpret the high-resolution dust images coming from ALMA", said Jaehan Bae, a co-author and researcher at the Carnegie Institution for Science in Washington, D.C.
Their technique successfully confirmed the existence of two previously predicted Jupiter-mass planets around the star HD 163296.
"Measuring the flow of gas within a protoplanetary disk gives us much more certainty that planets are present around a young star".
The two teams plan to apply their planet discovery technique to other protoplanetary discs. Although it has been very successful at uncovering thousands of new exoplanets, it can not be used to find ones around protostars.
A team led by Pinte found a planet about 39 billion kilometres (24 billion miles) from the star while Teague's team found two planets 12 billion and 21 billion kilometres (7.5 billion and 13 billion miles) out.
Unlike its older counterparts, young planets are surrounded by rotating disks of gas and dust, from which planets are formed. Subtle changes in the wavelength of this light due to the Doppler effect reveal the motions of the gas in the disc.
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. "We are now bringing ALMA front and center into the realm of planet detection", said coauthor Ted Bergin of the University of MI.
The system consists of three newly formed planets gravitating around a nearby star, dubbed HD 163296. "It is therefore crucial to study kinematics of gas to better understand what is happening in the disks we observe". While the young star is still surrounded by a gaseous disk in which the forming planets are embedded, these methods can not be used.
These initial observations, however, merely provided circumstantial evidence and could not be used to accurately estimate the masses of the planets. One astronomical unit is equivalent to the distance between the sun and the Earth or around 150 million kilometers.
The first is entitled "Kinematic evidence for an embedded protoplanet in a circumstellar disc", by C Pinte et al and the second "A Kinematic Detection of Two Unseen Jupiter Mass Embedded Protoplanets", by R Teague et al.