A group of astronomers have found the first direct evidence that groups of stars can rip apart their disk that forms the planets, causing it to be deformed. A new study, published in the journal Science, suggests that exotic planets could form oblique rings in curved discs around multiple stars. These results were made possible by observations with the European Southern Observatory’s Very Large Telescope (ESO VLT) and the Atacama Large Millimeter/Submillimeter Array (ALMA).
Our solar system is surprisingly flat – in it, all the planets rotate in the same plane. But this does not apply to all-star systems, especially to the disks that form planets around several stars, as the object of new research – the GW Orionis star system. This system, located just over 1,300 light-years away in the constellation Orion, consists of three stars and a warped, ruptured disk surrounding them.
“Our images show an extreme case where the disk is not flat at all, but deformed and has a displaced ring that has broken off from the disk,” says Stephen Kraus, professor of astrophysics at the University of Exeter in the UK.
To reach these conclusions, the team watched GW Orionis for over 11 years. “We found that the three stars do not orbit in the same plane, but that their orbits are offset from each other and from the disk,” says Alison Young of the Universities of Exeter and Leicester and a team member.
They also observed the system with the SPHERE instrument on VLT ESO and ALMA, in which ESO is a partner, and were able to image the inner ring.
An international team of researchers from the UK, Belgium, Chile, France, and the United States combined their exhaustive observations with computer simulations to understand what happened to the system. For the first time, they were able to clearly link the observed inconsistencies with a theoretical “disk rupture effect,” which suggests that the conflicting gravitational pull of stars in different planes can deform and break their disks.
Their modeling showed that the misalignment of the orbits of the three stars can lead to the fact that the disk around them breaks into separate rings, which they see in their observations. The observed shape of the inner ring also matches the predictions of numerical simulations of how the disk will rupture.
Future observations with ELT and other ESO telescopes could help astronomers fully uncover the nature of GW Orionis and reveal young planets forming around its three stars.