Keeping the line is not always easy in space. Some planets can increase in size up to 30%. Astronomers have not yet found an explanation for this phenomenon of transient planetary "fat", although they postulate that it could be related to the heating and cooling of gases.
Until now, scientists thought that since cold gas occupies less volume than hot gas, the planets known as? Hot Jupiters ? they shrunk as they lost heat . However, according to a new model developed by Laurent Ibgui of the University of Princenton and presented at the annual meeting of the American Astronomical Society, the volume of these celestial bodies fluctuates more than expected. Ibgui has come to the conclusion that when these planets revolve around their star in an elliptical orbit, "heat tides" are produced that heat the interior of the planet and counteract the cooling process. As a consequence, the planet expands, increasing its size by more than 30% , in a process that can last billions of years. If the planet's orbit changes and becomes more circular, the gas cools down again and the planet becomes thinner again.
