A gigantic, distant exoplanet about 40 times more massive than Earth, named TOI-849b, maybe the exposed core of the giant gas planet or a gas planet whose growth is stalled, according to a report by Space.com. An international team of researchers suspect that this exoplanet was somehow blown away providing an unusual chance to peek under the hood.
The researchers said that this giant planet may shed light on what the mysterious cores of giant planets look like.
Exoplanet TOI-849b
The exoplanet TOI-849b was first discovered by the Transiting Exoplanet Survey Satellite (TESS) of NASA in 2018. Its existence was later on confirmed by the La Silla Observatory in Chile. Scientists are investigating it as the alien world orbits the sun-like star TOI-849 about 730 light-years from Earth.
TOI-849b may nearly be as massive as Saturn since it has 40 times the mass of the Earth. Additionally, the exoplanet has a diameter of about 3.45 times that of Earth comparable to Neptune's, according to the data from the Paranal Observatory in Chile and the Las Cumbres Observatory Global Telescope. This plethora of information suggests that the exoplanet has a density similar to Earth and it is the densest Neptune-size planet ever discovered.
The exoplanet circles its star in its orbit for 18.4 hours making it very close to its star at a distance of just 1.5% of an astronomical unit (AU) which is the average distance between the Earth and the sun. Therefore, this newfound planet lies in the middle of the so-called Neptunian desert where Neptunian-size worlds orbit very closely to their stars.
Sean Raymond, an astrophysicist at the Observatory of Bordeaux in France commented that seeing this big planet close to its star in this in-between place is pretty cool as there are not so many planets in that area.
Remnant core of a gas giant
Nascent planets that are more than 10 to 20 times Earth's mass should swell to become gas giants like the Jupiter or Saturn. As such, one may think that this strange exoplanet may be a remnant of a gas giant that lost most of its weight somehow due to the heat it experiences orbiting so close to its star.
However, scientists noted that heating alone might still not strip a gas giant's atmosphere down to its core. Given the age of the star which is approximately 6.7 billion years old, they calculated that a Jupiter-size planet would have lost only a few percent of its mass because of the heat from its star.
Another explanation for the exoplanet losing its mass could be because of another mechanism. Maybe it collided with other giants; or maybe TOI-845b is in its current state has something to do with arrested development.
All in all, TOI-845b gives a glimpse to scientists as to how a giant planet's core looks like. Future scientists may directly observe TOI-845b core composition through analyzing evaporated material that remained in the atmosphere of the exoplanet.
There more to discover of this exoplanet whether it is a gas planet and whose atmosphere was stripped away by the stellar light.