Astronomers may have just found the first ever evidence of a planet orbiting three stars at the same time. Triple star systems make up only about 10% of all systems and much fewer planets have been detected in them compared to systems with just one star. That is why this newest research is incredibly significant as it may turn out to be the first ever discovery of its kind.
In the early part of 2020, astronomers were using the Atacama Large Millimetre/submillimetre Array (ALMA) and the European Southern Observatory’s Very Large Telescope (VLT) when they discovered a new star system close to the Orion constellation. Located about 1,300 light-years away from Earth is the GW Ori system that has three young stars. A massive gas and dust disk that looks like Saturn’s rings surrounds the newfound system. These disks are important in the early formation of new planets.
While this type of disk is actually quite common in young star systems, the one detected in GW Ori is incredibly odd as it contains an unexplained gap in between it that separates it into two portions. It was previously thought that the gap was caused by a gravitational torque caused by the three stars but new research has provided a different assessment.
In a new study, researchers from the University of Nevada believe that the reasoning behind the mysterious gap in the disk is actually caused by at least one young planet within the gas cloud of the GW Ori system. If they are correct in their theory, this would be the first ever detection of a circumtriple planet, meaning a planet that orbits three stars. This was reiterated in an interview with the New York Times when Jeremy Smallwood, who is a professor at the University of Nevada, Las Vegas, and the lead author of the paper, stated, “It may be the first evidence of a circumtriple planet carving a gap in real-time.”
Since the researchers can’t actually see the planet(s), they can’t confirm if they’re actually there or not. However, if there are “infant” planets in the system, experts believe that they are probably gas giants because of the gap in the dust cloud. A picture of the gas and dust disk surrounding GW Ori can be seen here.
The study was published in the Monthly Notices of the Royal Astronomical Society where it can be read in full.