Scientists have discovered a planet that is too large relative to its sun. This discovery challenges the laws of physics that govern the formation of the solar system and planets.
The planet found is thirteen times more massive than Earth. It is the most massive planet orbiting an ultracool dwarf star. Ultracool dwarf stars are the lightest and coldest stars in the universe, with temperatures of more than 2,400 degrees.
The star in question is nine times brighter than our Sun. The planet-to-star mass ratio is more than a hundred times that of the Earth to the Sun.
Princeton University, Leiden Observatory and the Netherlands Institute for Space Research (SRON) published the discovery on Thursday in the scientific journal Sciences. Physicists discovered the “very large” planet with the help of a spectrometer.
A spectrograph is an instrument designed to detect planets orbiting cool stars outside our solar system. This planet explorer specializes in discovering planets that have a liquid water surface, which is important for the emergence of life.
Although it is difficult to find such planets around stars like our Sun, they are easier to detect around ultracool stars. If the star is cooler, the planet must be closer to that star to obtain enough heat for liquid water to exist. If the planet is close enough to the dwarf star, it can be found by a slight change in the color of the star's light.
Physical theories need to be modified
The new planet has a heavy core. So heavy that according to current models, a large amount of material would be needed to form such a planet. But this amount was not present this time, because the matter orbiting a light star is much less than that orbiting a heavy star.
This discovery therefore contradicts current theories about planet formation around young stars. Stars form from large clouds of gas and dust. When a star is born, the remaining gas and dust form a rotating disk. Planets form in that disk, which is called the accretion disk.
According to physicists, it is impressive that the disk orbiting such a light star has enough mass to form a planet. According to theories, the dust mass would have to be ten times larger to form such a massive planet. But now that the planet has been discovered, scientists must modify current ideas about planet and star formation, SRON says.
