Tatooine from 'Star Wars' exists: a planet with a strange orbit has been discovered

GenevaLovers of the saga of Star Wars They should recall the magnificent sunsets seen from Tatooine, the home planet of protagonist Luke Skywalker, with two stars setting on the horizon. A similar scene can be seen from the planet that astronomers at the University of Birmingham have detected orbiting, for the first time, a binary system of two brown dwarf stars. However, the most remarkable aspect is that the planet's orbit follows a polar trajectory with a 90-degree inclination with respect to the plane in which the stars orbit.

The exoplanet was observed thanks to the European Southern Observatory's (ESO) Very Large Telescope (VLT), located at the Paranal Observatory in Chile, and represents the first evidence of a planet orbiting at right angles to a binary system. "We had some clues that these planets with perpendicular orbits around binary systems could exist, but until now we didn't have clear enough evidence," says Thomas Baycroft, a PhD student at the University of Birmingham and leader of the study published in Science Advances.

Binary systems with planets in polar orbits have previously been theoretically postulated, but the probability of finding them was thought to be relatively low. As a result, all of the 16 exoplanets discovered to date orbit binary systems orbit in the same plane as the star pair.

The pair of brown dwarf stars, known as 2M1510, were first detected in 2018 by Amaury Triaud, a professor at the University of Birmingham and also a co-author of the study. Brown dwarfs are a type of star that are slightly larger than a gas giant planet like Jupiter, but are smaller than ordinary stars. This makes them very faint, making them challenging to observe.

After analyzing the orbits of the two brown dwarfs in detail, the astronomers observed that the stars were following slightly erratic trajectories. This led them to believe that this disturbance was due to a planet orbiting the binary system at a 90-degree angle. "Finding a planet orbiting not just a binary system, but a binary system of brown dwarf stars, and with a polar orbit at that, is incredible and exciting," explains Triaud.

5,800 exoplanets discovered

The very faint brightness of brown dwarfs makes accurately determining the variation in the orbital velocity of these stars a complex task. The development of new analysis methods has made it possible to increase the precision of velocity measurements by a factor of 30 compared to previous similar observations orbiting the poles.

The authors of the study admit that the discovery was the result of chance, since the observations were not directly aimed at searching for the planet. They also highlight the presence of other factors in the orbits of brown dwarfs, such as the presence of a third brown dwarf, another sufficiently massive body orbiting at a great distance, or the presence of a disk of matter.

discovered to date, which now totals more than 5,800 and will continue to increase rapidly in the coming years.