A new triple system has now been discovered by the ALMA Observatory, and this stunning system contains misaligned rings of dust that have the potential to form planets. This system, GW Ori, has three inner stars, with the inner two orbiting 1 AU apart, and the outer star orbiting the inner two from a distance of 8 AU. These are comparatively the distances between the Earth and Sun, and slightly less than the Earth-Saturn distance when they’re closest. Surrounding these stars, ALMA has been able to resolve three misaligned dust rings that can’t be explained by just the stars’ motions. The innermost ring is tilted out of the plane of the outer two rings. All three dust rings contain sufficient material to form planets.
According to team member Nienke van der Marel: Our simulations show that the gravitational pull from the triple stars alone cannot explain the observed large misalignment. We think that the presence of a planet between these rings is needed to explain why the disk was torn apart. This planet has likely carved a dust gap and broken the disk at the location of the current inner and outer rings.
This work appears in The Astrophysical Journal with first author Jiaqing Bi, and it poses more questions than it answers. We can’t wait to see what we learn about this system over time.
“A Triple Star System with a Misaligned and Warped Circumstellar Disk Shaped by Disk Tearing,” S. Kraus et al., 2020 Sep. 3, Science
“GW Ori: Interactions Between a Triple-Star System and Its Circumtriple Disk in Action,” J. Bi et al., 2020 May 20, Astrophysical Journal Letters