Astronomers have announced the discovery of a new exoplanet in the Kepler-51 system. It is famous for its worlds having ultra-low density, comparable to the density of cotton candy.
The sun-like star Kepler-51 is 2,800 light-years away from Earth. Until recently, astronomers knew of three worlds orbiting around it. They are comparable in size to Saturn, but with only a few more times the mass of Earth.
Researchers believe that such worlds have tiny cores and huge atmospheres of hydrogen and helium, which explains their ultra-low density. But how exactly these strange planets formed, and how their atmospheres were not blown away by the intense radiation of the young star, is still a mystery.
To answer these questions, scientists decided to use the James Webb Telescope (JWST). Their target was the third exoplanet in the Kepler-51d system. Scientists were met with a surprise. The exoplanet passed in the background of its star two hours earlier than models predicted. After carefully examining new and archival data collected by various space and Earth-based telescopes, they concluded that the best explanation was the presence of an undiscovered fourth exoplanet. Its gravity affects the orbit of its neighbors, causing the timing of their transits to be out of sync with the estimated time.
The newly discovered exoplanet has a mass similar to other worlds in this system. It moves in a circular orbit with an orbital period of 264 days. At the same time, since the radius of this world is still unknown, it is too early to say that it also has ultra-low density.
It is also worth noting that the orbit of the fourth exoplanet passes inside the habitable zone. If it is not an ultra-low density world, but a more conventional super-Earth, it may have conditions on its surface that are conducive to sustaining life.
According to the researchers, they intend to continue studying Kepler-51 to understand the mystery of the formation of its worlds and find out if there are other, as yet undiscovered exoplanets in this system.
Provided by Phys.org
