Observers have seen a star devour its own planet. Earth might suffer the same fate. Scientists have, for the first time ever, witnessed a sun-like star consume a planet. Sadly, the discovery might also portend Earth's demise in five billion years. A team from MIT, Harvard University, Caltech, and other institutions described their observations of a Jupiter-sized planet spiraling close to a dying star 1,000 times its size over the course of 10 days in May 2020 in a study that was published in Nature on Wednesday.
The star, according to the scientists, continued to grow and became 100 times brighter in just 10 days before rapidly dissipating and returning to its usual state after the meal. Near the eagle-like constellation Aquila, 12,000 light-years from our galaxy, the planet perished. Kishalay De, a postdoctoral student at MIT and the study's lead author, stated in a news release that "we were seeing the end stage of swallowing."
It's a stark reminder of what many astronomers predict will most likely happen to Earth in the distant future when our own sun runs out of fuel, expands, and eats everything in its path, including the inner planets of the solar system. Fortunately, humans won't be present for the event. De said, "We are witnessing the future of Earth." If another civilization were to observe us from 10,000 light-years away as the sun engulfed the Earth, they would notice a rapid brightening as it expels material. They were followed by the formation of dust around it before the sun returned to its original state.
According to reports, the crew made the discovery by mistake. De was searching through data from the Zwicky Transient Facility at the Palomar Observatory of Caltech for evidence of binary star eruptions, in which two stars orbit one another and the brighter one periodically draws mass from the less brilliant one. "One night, I noticed a star that brightened by a factor of 100 over the course of a week, out of nowhere," De said. "I had never seen a stellar outburst like it," the author said.
De also observed that the source created compounds that could only exist in extremely cold environments, indicating that it was not likely a binary system. Low temperatures and burgeoning stars don't mix, according to De. The team was able to confirm the existence of cold material that seemed to stream out from the source throughout the course of the following year using additional observations made with an infrared camera at the Palomar Observatory.
The researchers identified the cause of the cool outburst after making more measurements with NASA's infrared satellite observatory NEOWISE and discovering that the total energy released by the star since it brightened was only 1/1,000th the magnitude of any previously reported steller mergers. Accordingly, De said, "whatever merged with the star has to be 1,000 times smaller than any other star we've seen."