Researchers at the University of Warwick have led a team that has discovered the first exposed core of a planet. The scientists describe the planet as highly unusual, and it was found in the Neptunian Desert where such massive objects are rarely seen. The researchers believe that the planetary core could be a failed gas giant or one that had its atmosphere ripped away.
The object provides an opportunity to analyze the interior of a planet firsthand. The planetary core is about the same size as Neptune in our solar system. The discovery is believed the be the first time that an exposed planetary core has been observed.
The planetary core is located around a star that’s very much like our Sun and is approximately 730 light-years away. The object is named TOI 849 b in orbits so close to the host star that its year lasts only 18 hours. The surface of the planetary core is around 1800K. TOI 849 b was discovered in a survey of stars made by NASA’s TESS using the transit method.
Neptunian Desert is a term used by astronomers for the zone close to stars where we rarely see planets of the size of Neptune’s mass or larger. When TESS discovered the planetary core, the transit signal was confirmed and refined using observations from 10 telescopes of the Next-Generation Transit Survey at the Paranal Observatory in Chile. The object was also analyzed using the HARPS instrument at the La Silla Observatory in Chile.
The data allowed the team to determine that the object’s mass is 2 to 3 times higher than Neptune while being incredibly dense. The team says that the planet is the most massive terrestrial planet with an Earth-like density that has been discovered. The team says that you would expect a planet this massive to have accreted large quantities of hydrogen and helium when it formed growing into something similar to Jupiter. Since those gases aren’t seen, the object has to be a planetary core.