Astronomers at MIT have discovered a rocky exoplanet orbiting the bright K-dwarf star BD+05 4868A. The planet, named BD+05 4868Ab, has a mass similar to that of Mercury and orbits its star just 20 times closer than Mercury does to the Sun. With an orbital period of only 30.5 hours, the planet is scorching hot, with surface temperatures reaching up to 1,600 degrees Celsius.
The exoplanet’s close proximity to BD+05 4868A leads to an enormous amount of surface minerals being evaporated into space, creating a comet-like tail that stretches up to 9 million kilometers long. This tail is composed of debris shed from the planet as it orbits its star and is estimated to be equivalent in size to one Mount Everest every time the planet passes.
The discovery was made possible by data from NASA’s Transiting Exoplanet Survey Satellite (TESS), which detected unusual transit depths that indicated the presence of a comet-like tail. This finding is significant, as scientists have only previously identified three other disintegrating planets beyond our Solar System, all of which were discovered over 10 years ago using data from NASA’s Kepler Space Telescope.
The newly discovered exoplanet, BD+05 4868Ab, holds the record for the longest and deepest comet-like tail among known disintegrating planets. The team predicts that this planet will disappear in approximately 1 million to 2 million years, making its evaporation the most catastrophic of all known cases.
Source: https://www.sci.news/astronomy/disintegrating-exoplanet-comet-like-tails-13848.html