ALMA discovers trio of exoplanets
ALMA has uncovered a trio of exoplanets, the first time the array has made such a discovery.
A trio of infant planets have been found around a young star using the Atacama Large Millimeter/submillimeter Array (ALMA).
These are the first planets that have been found using ALMA, and they were uncovered by using a new technique which searches for unusual patterns in the ring of dust that surrounds the star known as a protoplanetary disc.
“Measuring the flow of gas within a protoplanetary disc gives us much more certainty that planets are present around a young star,” says Christophe Pinte of Monash University in Australia.
“This technique offers a promising new direction to understand how planetary systems form.”
Pinte lead one of two teams which analysed observations of the star HD 163296 and its surrounding protoplanetary disc.
HD163296 is a youthful four million years old (the Sun is 1,000 times that age) but with a mass twice that of our star.
The two teams looked at the carbon monoxide in the protoplanetary disc, searching for the subtle disturbances caused by a massive object, such as a planet, passing through.
This technique uncovered several rings of concentric circles in the disc, gaps in the gas which could have been caused by planets.
Previous studies of the system had also seen gaps in the dust in the same place lending even more weight to the discovery.
Teague’s team found two gaps in the gas around 12 billion and 21 billion km from the star (around 80 and 140 times the Earth-Sun distance), while Pinte’s group identified a potential planet at 39 billion km (260 times the Earth-Sun distance).
“This entirely new approach could uncover some of the youngest planets in our galaxy, all thanks to the high-resolution images from ALMA,” says Richard Teague from the University of Michigan.