Planets discover orbits horizontally around double stars

In a discovery that challenges conventional understanding of planetary systems, astronomers have discovered a planet perpendicular to its host star. The researchers used the very large telescope (VLT) of the Southern European Observatory to identify this unique configuration, surrounding a pair of brown dwarves-the object is larger than the gas giant, but too small to be a suitable star.

The discovery marks the first strong evidence for a planet to rotate at a 90-degree angle to the orbital plane of its binary galaxy, a configuration that astronomers have theorized but never confirmed.

“I’m very happy to be involved in detecting reliable evidence of the existence of this configuration,” said Thomas Baycroft, a PhD student at the University of Birmingham.

The planet, named 2M1510 (AB)B, erodes each other in orbits near two brown dwarves when viewed from Earth. The system represents a significant rarity in astronomy, with only the second pair of known eclipse brown dwarves, now the first planet with a confirmed “polar” orbit.

Brown dwarves occupy a strange middle ground in cosmic classification – very easily considered a planet, but lack sufficient mass to maintain the nuclear fusion that drives the stars. Therefore, they are sometimes called “failed stars.”

The research team was not initially looking for planets. When they noticed something unusual, they were using the UV and visual trapezoidal spectrometer (UVE) on the Chilean VLT to perfect the measurements of the brown dwarf.

“In a sense, this discovery was accidental, because our observations were not collected to seek such a planetary or orbital configuration,” explained Amaury Triaud, a professor at the University of Birmingham and co-author of the study. “So, it was a big surprise.”

Most known planets that rotate binary stars travel on the same plane in orbit with each other, just as the planets in our solar system are roughly aligned with the sun’s equator. However, this new planet is traveling in orbits perpendicular to its host star, just like the vertical rings of the North Pole and the South Pole of the binary system.

The researchers indirectly detected the planet by observing its gravity on the orbit of the brown dwarf. After careful analysis and elimination of alternative explanations, they concluded that planets in polar orbits are the only situation consistent with the observations.

This unusual configuration goes beyond its novelty. It provides key insights into the formation of planetary systems and the diversity of planetary systems in our galaxy. Theoretical models show that this configuration is possible, with astronomers having previously detected gas and dust disks that can form polar directions around binary stars, but this is the first confirmed planet in this arrangement.

The 2M1510 system is relatively close to the Earth in astronomy. The brown dwarf pair was first discovered in 2018 by Professor Triaud and his colleagues using Speculos, a habitable planet far from super cool stars, another facility at the Paranal Observatory.

While the exact mass and orbital period of the Earth are still uncertain, the team estimates that if the planet orbits a binary stable boundary, its mass is about 10 times the mass of the Earth and the circular dwarf every 100 days.

The researchers hope to further study the system through other observations to perfect the characteristics of the Earth. Professor Triaud believes that this discovery proves what is yet to be discovered in our cosmic community: “In general, this shows this to our astronomers, but also shows the entire public what is possible in the fascinating universe we live in.”

The study was published in Science Development and was published in the contributions of researchers at the University of Birmingham, Cambridge and institutions in Portugal and France, UK.