Exoplanet that lost its gasDate: 16 April 2020 Tags: Space
Scientists claim that a previously found exoplanet, which is 40 times more massive than Earth, could be the remnant core of a giant planet.
The interiors of gas giants like Jupiter and Saturn remain poorly understood. This opens up the window of opportunity to shed light on what the mysterious cores of giant planets look like.
A new study suggests that the exoplanet TOI-849b may be the remnant core of a giant planet or a giant planet in the making whose growth stalled.
NASA’s Transiting Exoplanet Survey Satellite (TESS) first detected the exoplanet TOI-849b in 2018. La Silla Observatory in Chile helped confirm its existence later on. The exoplanet orbits the sun-like star TOI-849, which is about 730 light-years from Earth.
The exoplanet TOI-849b has around the same diameter as that of Neptune, which is around 3.45 times that of Earth. It circles its star in a fast, tight orbit at the distance of just 1.5 per cent of an astronomical unit (AU), the average distance between Earth and Sun that is around 150 million kilometres. TOI-849b takes only 18.4 hours to complete a revolution around its sun TOI-849.
As per previous models, nascent planets that have a mass more than 10 to 20 times that of Earth should have strong enough gravitational fields to gobble up huge amounts of material from the protoplanetary disks of gas and dust that surround their newborn stars, thus swelling up to become gas giants similar to Jupiter or Saturn.
Scientists believe that even though TOI-849b orbits so close to its star, heating alone might not be responsible for the gas giant’s atmosphere losing all its weight. They believe that TOI-849b could have collided with other giant planets or the gravity of its star could have peeled off much of its gas envelope.
Another possible explanation forwarded by scientists is that the planet could have formed later when much of its system’s protoplanetary disk was gone.
There is also a possibility of TOI-849b forming in orbit around its star carving off all the material available to it for its growth within the protoplanetary disk.