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The WASP-18b exoplanet is a giant world orbiting a WASP-18 star, located about 330 light-years from Earth, in the constellation of Phoenix. It is estimated that the mass of WASP-18b is about ten times that of Jupiter. However, it orbits the star once every 23 hours, while the fifth planet in the Solar System takes about 12 years to complete a revolution around the Sun. They are located in the category of "hot Jupiter", or massive planet very close to its star Outside the Solar System. The exoplanet is about 3 million km from its star.
The size of WASP-18b is so large and is orbiting so close to the star that it can not be understood how stellar currents have not destroyed it. The only explanation that astronomers can give is that the stellar currents of that system are weaker than those of the solar system or that there could be another unidentified element that prevents the collision between this exoplanet and its star.
The main peculiarity of the exoplanet, according to Chandra's new data, is so close to its star that it may be causing the damping of its magnetic field. That is causing your star to behave like a star that has aged, before time.
Young stars (such as Wasp-18) tend to be very active, possess very strong magnetic fields, emit large amounts of x-rays far superior to the more "old" stars. All these characteristics are closely linked to their rotation speed, which generally slows down with age. However, when astronomers focused their instruments on Wasp-18, they barely detected x-ray emissions. In fact, the star was about 100 times less active than it should be by its age.
Domino effect
The researchers believe that the tidal forces created by the gravitational pull of the huge exoplanet, similar to the earth tides created by the Moon, but on a much larger scale, may have destabilized the star's magnetic field. The intensity of the magnetic field depends on the amount of convection that is given in the star, that is to say, how intensely the hot gases within it are stirred. This causes a domino effect resulting in a weaker magnetic field and premature aging of the star.
Wasp-18 is particularly sensitive to this effect because its convection zone is narrower than that of other stars. And that makes it more vulnerable to the impact of the tidal forces pulling it. The effect caused by the tidal forces of the exoplanet may also explain the large and small amount of lithium found in Wasp-18. Lithium generally abounds in the youngest stars, but with the passage of time convective movements carry much of the lithium to the deepest and hotest areas of the star where it is destroyed by nuclear reactions.
