Science News

Circumplanetary disc discovered around planet 370 light years away

A circumplanetary disk was sighted by a group of astronomers through the Atacama Large Millimeter / submillimeter Array (ALMA). This is the first time, according to the same researchers, that a disk of planetary material is identified by optical light, composed mainly of dust and gases which are the remnants of the formation of a planet.

The disk has been identified around PDS 70 c, a planet that orbits PDS 70, a young star that is at a distance of 370 light-years from us. PDS 70 c is an external planet that is at a distance from its star similar to the distance between Neptune and the Sun.

This planet had already been identified along with another gaseous planet, PDS 70 b, which is located at a distance from its star similar to that which separates Uranus from the Sun and which presents a mass of dust that resembles a tail.

“For the first time, we can definitely see the telltale signs of a circumplanetary disk, which helps support many of the current theories on planet formation,” explains Andrea Isella, a researcher at Rice University in Houston and one of the authors of the study. The astronomer thinks that the material that circulates around this planet, formed relatively recently, is favoring the formation of moons of planetary dimensions.

The identification at the level of optical light of the disk around PDS 70 c was possible thanks to ALMA which analyzed in particular millimeter and submillimetre wavelengths, wavelengths at which the stars emit relatively little light and are therefore not in able to completely hide planets and elements that revolve around them, with their brightness.