Astronomers Spot First-of-Its-Kind Planet Disintegrating and Shedding Debris From a ‘Comet-Like’ Tail

Planets have been one of the most analyzed astronomical bodies in space. Despite decades of research, new findings indicate that these bodies may not be an open book for experts, stated the Independent. In a study published in The Astrophysical Journal Letters, researchers discussed some first-of-its-kind features observed in a planet outside the solar system.

The subject of the study is BD+05 4868 Ab, situated 140 light years away from Earth. It is present inside the Pegasus constellation, in space. Experts noted that the signal, which typically comes from stars of these planets, was different from what was noted in other similar systems. Usually, there is a brief dip in the light that is emitted by the star. This is because the planet orbits in front of the star, and for a while blocks its light from coming to the faraway observer. 

In this case, though, the dip lasted longer than usual. On further examination, the team concluded that even after the planet had passed in front of the star, a trailing structure still blocked the light. Another thing they noted was that the dip's size changed with every revolution. This implied that the planet's size was not the same at every turn. Astronomers discovered the phenomenon using NASA’s exoplanet surveying satellite. 

Researchers claimed that the trailing structure looks like a comet-like tail composed of debris, according to MIT. "The extent of the tail is gargantuan, stretching up to 9 million kilometers long, or roughly half of the planet’s entire orbit," said Marc Hon, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research. Experts think the tail is a result of this particular planet's crumbling and shedding material from its body. Hence, after every revolution, the light's depth changed. Experts further added that debris equivalent to one Mount Everest was shed during one orbit.

The planet is the size of Mercury, and is 20 times closer to its star. Examinations suggest that it takes 30.5 hours to complete one revolution. Considering the size and the amount of material shed by the body, researchers believe BD+05 4868 Ab will disintegrate in around one million to two million years. The team thinks that the planet's proximity to the star could be one reason why it is evaporating at such a high rate. The star is possibly boiling any minerals on the planet's surface, which are then escaping to space. The planet's low mass implies weak gravitational pull, which makes it difficult for the body to hold on to its environment. As a result, the planet will continue to lose its mass till it reaches its effective 'demise.'

Researchers think that the planet is on its 'last breath.' The team is ecstatic to have discovered this body, especially when they originally did not head out to find such extraterrestrial bodies. "We weren’t looking for this kind of planet," Hon said. "We were doing the typical planet vetting, and I happened to spot this signal that appeared very unusual."

To date, astronomers have uncovered around 6,000 planets, according to Discovery Magazine. They have only found three other planets similar to BD+05 4868 Ab. Even amongst them, this particular planet has the longest tail and the greatest depth. Researchers are hopeful that soon they will get the opportunity to examine the planet using the James Webb Space Telescope. Their objective will be to understand the interior of this planet and its habitability.