TORONTO -- New research into a stellar system where three stars compete for attention has unearthed the first evidence that stars can rip apart and warp massive discs of planet-forming material.
Researchers identified a specific star system where planets are not formed on an even plane like in our solar system, but instead on an “inclined” ring within a “warped circumstellar disk around multiple stars,” a press release stated.
The system is called GW Orionis, and is located 1,200 light years away in the constellation of Orion.
According to researchers, if you were standing on a planet inside this star system, you could be treated to a double, or even a triple sunset, similar to the iconic Star Wars planet Tatooine.
Published in Science Mag last week, the new observations of GW Orionis provides the first concrete evidence for theoretical models that predicted if the planet-forming disc around a star system was misaligned with the orbital plane of the stars themselves, gravitational forces from the multiple stars could warp the disc and actually break it into rings, something called disc tearing.
An international team led by researchers from the University of Exeter used data from several large telescopes or arrays and a new infrared imager, called MIRC-X, to gain these new insights into the star system.
In star formation, a disk of dust and gas swirls around the growing star, feeding it. Once the star has formed, leftover material within that circumstellar disk forms into planetary bodies and moons.
"We're really excited that our new MIRC-X imager has provided the sharpest view yet of this intriguing system and revealed the gravitational dance of the three stars in the system,” said Stefan Kraus, professor of astrophysics at the University of Exeter, in the press release. “Normally, planets form around a flat disc of swirling dust and gas — yet our images reveal an extreme case where the disc is not flat at all.
"Instead it is warped and has a misaligned ring that has broken away from the disc. The misaligned ring is located in the inner part of the disc, close to the three stars.”
Researchers confirmed the existence of this misaligned ring by observing the shadow of the inner ring as it was cast on the rest of the disc.
An artist’s rendering of the star system shows what looks like a smaller ring of dust and gas tilted in opposition to a more oval disc of material rotating around it.
The inner ring alone contains enough dust and gas to make the mass of Earth 30 times over, meaning it is more than capable of forming planets. If planets could be formed on an inner ring like this, in this star system and others, this means we could see more star systems where planets orbit in increasingly unique ways.
And it could mean there are already planets out there that we haven’t discovered in star systems we’re already aware of, on wide and oblique orbits.
"Since more than half of stars in the sky are born with one or more companions, this raises an exciting prospect: there could be an unknown population of exoplanets that orbit their stars on very inclined and distant orbits,” Alexander Kreplin, of the University of Exeter, said in the press release.
It’s not just the discs of dust and gas that are misaligned with each other, but the stars themselves. The research team observed GW Orionis carefully for more than 11 years, and observed that the orbit of the stars are not on the same plane, but are also misaligned.
The final step for researchers was to take the painstaking observations and load them into computer simulations. This was when it became clear to researchers that they had clear evidence that the discs were torn apart by the competing gravitational forces of the three misaligned stars, proving what had long been only theory.
If three suns, one solar system seems like a familiar scenario, there might be a reason for that.
It’s a real-life example of the “Three-Body Problem,” both a real scientific theory -- a physics and classical mechanics problem trying to track how three objects would move around a single gravitational point -- and a Hugo Award-winning science fiction novel by Chinese writer Liu Cixin that describes the exact scenario occurring in the new research: a star system with three stars in an unstable orbit.
So far, the new research has not predicted an imminent alien invasion to match the events of the novel, so some parts at least, remain science fiction.