Astronomers have detected one of the youngest alien worlds ever found. Unfortunately, this newly born planet is already dying.
The exoplanet dubbed PTFO 8-8695 b is a Jupiter-like world located in the Orion constellation, 1,100 light-years away from Earth. Cloaked in a cloud of gas and having twice the mass of Jupiter, this planet is very close to its star that it only takes just 11 Earth hours for it to make a full orbit.
The planet orbits a star estimated to be between 2 million and 3 million years old. In comparison, the Earth's sun is about 4.6 billion years old. The ancient human species Homo naledi roamed the Earth about 2 million years ago, which means that the star system is just about the age of human ancestors.
The discovery of PTFO 8-8695 b is remarkable in that most of the 3,300 plus exoplanets that astronomers have detected orbit middle-aged stars just like the solar system's sun. Prior to its discovery as a candidate planet in 2012, scientists did not even think that gas giants could thrive around very young stars.
"In 2012, there was no solid evidence for planets around 2 million-year-old stars," said Lowell Observatory astronomer Lisa Prato.
The planet's short orbital period made it easier for researchers to study the planet, but its proximity from its star also appears to be the reason why this baby planet is already falling apart.
The strong gravity of the host star is ripping away the outer layers of PTFO 8-8695 b, as hinted by spectroscopic observations, which revealed the hot Jupiter is only about 3 to 4 percent the size of its host star, and hydrogen emission observations.
"The gas has to be filling a much larger region where the gravity of the planet is no longer strong enough to hold on to it. The star's gravity takes over, and eventually the gas will fall onto the star," said astronomer Christopher Johns-Krull from Rice University.
Johns-Krull said that the planet may have been born farther away from its host star, but it later on migrated to a point where it is now being destroyed.
The astronomer said that there are close-orbiting planets circling middle-aged stars that are presumed to be in stable orbits, but there is uncertainty with how quickly PTFO 8-8695 b would lose its mass and if it will lose too much to be able to survive.
The findings of the study are set to be published in The Astrophysical Journal.
