Hon et al., APJL, 2025
It is one of the least habitable planets that there are records: a planet that is being destroyed by its own host star.
The “infernal” landscape, as described a, BD+05 4868 Ab liquid rock. And worse: this seething magma is drain to the space, and has already left a trail of 9 million kilometers – twice the diameter of this unfortunate planet.
But why? This planet is about 140 light years away, orbiting its host star every 30.5 hours. This puts it about 20 times closer to the star than Mercury orbits the sun. It is his own host who is killing him, which makes him one of the most uninhabitable planets known to the scientific community.
The BD+05 4868 AB is getting smaller and smaller, and may have already had twice its current size. In each orbit, ejects for the space an amount of material equivalent to a lot of Evereste And at this rhythm, it will dissolve completely within 1 or 2 million years.
“This is a very small object, with a very weak severity, so it easily loses a lot of mass, which further weakens its severity, so it loses even more mass,” says Avi Shporer, astronomer of the Transiting Explanet Samatelite mission (Tess) and one of the new authors on this planet, published in The Astrophysical Journal Letters. “It’s a uncontrolled process And it’s only getting worse for the planet. ”
It is only the fourth melted mercury exoplanet discovered to date, through the traffic method (observation of periodic falls of brightness), but also the most counted days.
“The shape of traffic is typical of a comet with a long tail,” says astrophysicist Marc Hon. would not survive a long time for such a large proximity to the host star. However, evaporated mineral grains of the planetary surface can last enough time to have such a distinct tail. ”
Now scientists want to “directly measure the inner composition of a rocky planet, which can tell us a lot about the diversity and potential habitability of terrestrial planets outside our solar system.”
