An international team of astronomers discovered a planet that would have been born from several planets: its name is TOI-1853b. It is a super planet made up of others.
Although it is the size of Neptune, its mass is almost twice that of any other celestial body of similar size, and its density is incredibly high. This means that it is made up of a larger fraction of rock than would normally be expected at that scale.
The researchers suggest that all this is the product of planetary collisions: the gigantic impacts removed some of the lighter atmosphere and water, leaving behind a multitude of rocks.
Luca Naponiello, from the University of Rome Tor Vergata, he was in charge of the investigation, leading an international team. The results of the study were published in Nature.
The exoplanet TOI-1853b is located approximately 167 parsecs (545 light years) from the Sun, in the constellation Bootes. It orbits every 1.24 days around the star TOI-1853.
“We had not previously investigated such extreme giant impacts,” says the astronomer Zoë Leinhardt, from the University of Bristol.
With a size similar to that of Neptune (the fourth largest planet in the Solar System has a radius of 24,622 kilometers), TOI-1853b represents an enigma for scientists.
“We know that there is a huge diversity of planets in exoplanetary systems,” says Phil Carter, from the University of Bristol, who is part of the research. “Many have no analogues in our Solar System, but often have masses and compositions between those of the rocky planets and Neptune/Uranus”.
“We found that the initial planetary body probably would have needed to be rich in water and undergo an extreme giant impact at a speed greater than 75 km/s to produce TOI-1853b as observed,” adds Carter.
According to the researchers, the collisions of different exoplanets removed part of the lighter atmosphere and water, leaving a planet of high density, substantially enriched with rocks.
“It is not something we expected. There is a lot of work to be done to improve the material models underlying our simulations and expand the range of modeled extreme giant impacts,” Leinhardt says.
It is the mother of all planets, a super planet made up of others.