Astronomers believe they may have found the first direct evidence of a new planet being born.
A dense disc of dust and gas has been spotted surrounding a young star called AB Aurigae, around 520 light years away from Earth.
The swirling disc is one of the telltale signs of the star system being born in the constellation of Auriga, the scientists said.
Dr Anthony Boccaletti, who led the study from the Observatoire de Paris, PSL University, France, said: “Thousands of exoplanets have been identified so far, but little is known about how they form.”
Until now astronomers had been unable to take clear images of young discs to see these twists.
Dr Boccaletti and his team of astronomers used VLT’s Sphere instrument to take photos of AB Aurigae, which show “a stunning spiral of dust” caused by the baby planet trying to “kick” the gas.
The same instrument was used in 2018 to take photos of another infant planet, thought to be just 5.4 million years old.
According Emmanuel Di Folco, of the Astrophysics Laboratory (LAB) of Bordeaux in France and one of the study authors, this so-called kicking phenomenon causes “disturbances in the disc in the form of a wave, somewhat like the wake of a boat on a lake”.
As the new planet rotates around AB Aurigae, it causes the surrounding gas and dust to be shaped into a spiral arm.
Anne Dutrey, also at LAB and a study co-author, said: “The twist is expected from some theoretical models of planet formation.
“It corresponds to the connection of two spirals – one winding inwards of the planet’s orbit, the other expanding outwards – which join at the planet location.
“They allow gas and dust from the disc to accrete onto the forming planet and make it grow.”
– The observations are reported in the journal Astronomy & Astrophysics.
