Rapidly Dissolving Exoplanet Discovered

A research team from the United States has made an intriguing discovery of an exoplanet that is losing material at an unprecedented rate, trailing a comet-like tail that extends for half of its orbit around its star. The Massachusetts Institute of Technology (MIT) announced the finding of this dying celestial body, which has a mass comparable to Mercury but orbits much closer to its star than any planet in our solar system. The exoplanet, designated BD+05 4868 Ab, completes an orbit in approximately 30 hours, shedding material equivalent to the mass of Mount Everest with each revolution. It is projected to completely disintegrate within one to two million years.

The exoplanet was discovered almost by chance, as the researchers were not actively searching for it. They noted an unusual signal in the data collected by the Transiting Exoplanet Survey Satellite (TESS), which is designed to detect periodic dimming of stars that may indicate the passage of planets in front of them. Typically, such dimming events are brief, with stars returning quickly to their original brightness. In this case, however, the star remained dim for an extended period, and the intensity of the dimming fluctuated, resembling the signature of a comet with a lengthy tail.

Using orbital data and the peculiar dimming patterns, the team deduced that the exoplanet is likely a rocky body with a tail that could stretch up to nine million kilometers. Unlike the gas and ice composition of a typical comet's tail, this exoplanet's tail is believed to consist of minerals. The surface temperature of the exoplanet is estimated to be around 1600 degrees Celsius, causing any rock present to vaporize and escape into space due to the planet's relatively low mass. Observing this phenomenon can be likened to witnessing the final breaths of a celestial entity, with its demise approaching rapidly in astronomical terms.

Among the nearly 6,000 known exoplanets, BD+05 4868 Ab is not the first to exhibit signs of disintegration; the research team identified three others. However, none of these previously observed exoplanets have demonstrated a tail of comparable length or caused similar levels of star dimming. This unique situation suggests that the demise of BD+05 4868 Ab is significantly more severe than that of its counterparts, indicating a much quicker disappearance. The team intends to utilize the James Webb Space Telescope to analyze the composition of the exoplanet's tail and to explore the possibility of discovering additional similar exoplanets.

This discovery will be detailed in the upcoming edition of the Astrophysical Journal Letters.