A large extraterrestrial discovery orbiting the largest star system known to date

The Very large telescope The European Southern Observatory captured images of a giant planet orbiting the binary system b Centauri. However, the latter is particularly hot and massive (according to experts 6 to 10 solar masses). Scientists previously thought that a giant planet was unlikely to form around such large stars. This discovery calls into question some theories regarding the formation of planets.

Previous studies of planets in close orbit around heavier stars have shown that the frequency of giant planets increases with the mass of the star to a certain point (up to 1.9 solar masses), and beyond that their frequency decreases rapidly. This suggests that the formation of planets around more massive stars is more difficult, if not impossible, and that giant planets orbiting stars beyond 3 solar masses are rare or non-existent.

This belief is now being questioned: astronomers are proving that planets can orbit galaxies much larger than predicted by theoretical models. The planet in question, called b Centauri b, is 560 times (or 560 AU) farther from its star than the Earth-Sun distance. It is 10 times larger than Jupiter. The planetary / star mass ratio is estimated to be 0.10–0.17%, which is similar to the Jupiter / Sun ratio, but the distance between b Centauri b and its star is about 100 times greater than that between Jupiter and the Sun.

The largest star system ever discovered

Planet B Centauri is located at P325 Light years Earth, in the Centaur constellation. This is the first time the observation of a planet around such a large galaxy has been confirmed. ” The discovery of a planet around B Centauri is very exciting because it completely changes the image of massive stars like the hosts of the planets. », Marcus Johnson explains, Astronomer and associate professor at the University of Stockholm Research related to the invention.

⁇ We have always had a solar system-centered view of what planetary systems should look like. Over the past ten years, the discovery of many planetary systems in astonishing and unprecedented formations has broadened our historically narrow view. », Underlines Matthias Samland, researcher Astronomy Max Planck Institute And co-author of the study. Image taken by SPHERE tool (Spectro-polarimetric high-contrast exoplanet research) Very large telescope, Using a chronograph, which blocks the intense light emitted by the binary system to better differentiate the planet. ESO says SPHERE has already successfully imaged many planets orbiting stars other than the Sun In a press release.

The B Centauri binary system is the largest star system ever discovered. Most massive stars are very hot, and this system is no exception: its main star is called the Type B star, which is three times hotter than the Sun. Due to their high temperature (10,000 to 30,000 K), these stars – known as blue giants – emit intense ultraviolet and X-rays, however, these high-energy radiations cause rapid evaporation of light, the surrounding material, and potential impact. The process of formation of nearby planets. ” Type B stars are generally considered destructive , Johnson confirms.

A training process that is mysterious

However, the discovery of b Centauri b shows that planets can successfully form even in such difficult conditions. The planet’s largest orbit (560 AU) – one of the largest ever discovered – could explain how its star’s radiation escaped.

Another property that distinguishes this new Exoplanet is the relative youth of its stellar system, in which the two stars are each 15 million years old (4.6 billion years from our Sun). According to researchers, the formation of b Centauri b is unlikely In place Through the conventional mechanism of cardiac augmentation – a model of planetary formation, through which solid particles of the protoplanetary disk of the star come together to form a solid body, large enough to receive gravitational force.

On the contrary, they suggest that it may have formed elsewhere and ended up with dynamic interactions in its current location or formed by ‘gravity instability’ – which assumes that it ‘collapses itself under the influence of a part of the protoplanetary disk’. Its own gravity. ” When this happens, a small secondary body is formed and begins to orbit the star. », Caitlin Grotter explains, From the Steward Labs at the University of Arizona.

ThanksVery large telescope With ESO’s new technological advances set to open in 2025, astronomers will no doubt be able to learn more about the planet’s formation and properties. ” Finding out how it came to be would be an enigmatic task, which is currently a mystery. , Johnson concludes.

Source: M. Johnson et al.