The discovery of a rare planet with three suns in the constellation Orion

An international team of astronomers have presented a new study that explains the anomalous structure of the GW Orionis triple star system in the constellation Orion.

There is now more evidence that the bizarre star system perched in the nose of the constellation Orion may contain the rarest type of planet in the known universe: a tiny exoplanet orbiting three suns simultaneously.

The star system, known as GW Orionis (or GW Ori), located about 1,300 light years from Earth, is a tempting target for study. With three intertwined dusty orange rings, the system literally looks like a giant bull’s eye (circles that people shoot arrows at in an attempt to hit the center of the target) in the sky.

In the middle of these circles live 3 stars, two of which are trapped in a narrow binary orbit with each other, and the third orbit widely around the other two stars.

Scientists took a closer look at GW Ori using the Atacama Large Millimeter / submillimeter Array Telescope (ALMA) in Chile, in a study published in 2020 in The Astrophysical Journal Letters. They found that the system’s three dust rings are in fact out of balance with each other, with the innermost ring oscillating violently in its orbit.

The team suggested that a small planet could upset the gravitational balance of GW Ori’s complex three-ring arrangement. If the discovery is confirmed, it will be the first triple-sun (or “round”) planet in the known universe.

Now, an article published on September 17 in the journal Monthly Notices of the Royal Astronomical Society provides new evidence for the existence of this rare planet. The research team ran a 3D simulation to model how mysterious gaps in the rings of the star system might form, based on observations of other dust rings (or “protoplanetary disks”) elsewhere in the universe .

The team tested two hypotheses: either the gap in the rings of GW Ori formed from the torque (rotational force) applied by the three rotating stars at the center of the system, or it appeared when a planet formed inside one of the rings.

Scientists concluded that there was not enough turbulence in the rings for the stellar moment theory to work. Instead, the simulations suggest that a massive planet the size of Jupiter, or perhaps several, is the most likely explanation for the rings’ strange shape and behavior.

If future observations of the system support this theory, GW Ori could be “the first evidence of a circular planet digging a hole in real time,” Jeremy Smallwood, lead author of the study, told The New York Times. University of Nevada in Las Vegas.

Source: Sciences en direct