Two years ago, a star in its final stages of life was accused of consuming a planet within a system located 12,000 light-years from Earth. However, new evidence has surfaced, suggesting a different scenario. According to astronomers, observations made using the James Webb Space Telescope—conducted in collaboration with NASA and European and Canadian space agencies—indicate that while the planet did end up inside the star, the circumstances were not as initially believed.
The initial theory proposed that the star expanded into a red giant, which then engulfed the Jupiter-sized planet. However, new observations revealed that the planet’s orbit gradually decreased over time, bringing it ever closer to the star until a collision occurred. This suggests that the planet was more responsible for the event by essentially moving into the star’s path.
Ryan Lau, an astronomer at the National Science Foundation’s NOIRLab, explained to Mashable that while the star consumed the planet, the process was different than originally thought, with more fault lying with the planet.
Previous research published in the journal Nature provided the first direct evidence of a star engulfing a planet as it happened. The event was initially detected five years ago as a sudden bright flash of visible light named ZTF SLRN-2020. Earlier infrared observations had noted a glow around the star, indicating the presence of dust potentially from a destroyed planet.
Scientists initially believed the star had turned into a red giant, capable of consuming nearby planets. However, new data from the James Webb Space Telescope revealed that the star did not brighten, as would be expected if it had expanded. Instead, the star remained relatively constant in size, while the Jupiter-sized planet moved closer over millions of years, eventually grazing the star’s outer atmosphere until it was fully absorbed.
Results and new interpretations of the event are published in The Astrophysical Journal. The collision resulted in a massive explosion and the formation of a swirling disk of gas and dust, with molecules like carbon monoxide detected by the telescope.
Morgan MacLeod from the Harvard-Smithsonian Center for Astrophysics noted that the planet began to interact with the star’s atmosphere, leading to an increasingly rapid descent into the star, effectively creating a ring of material around it.
Unlike giant stars that end in a supernova and collapse into a black hole, medium-sized stars like the sun die more slowly. They form “planetary nebulae,” clouds of gas and dust created as these stars lose nuclear fuel. This process is expected to be the sun’s fate in about five billion years, though much about these events remains unknown.
Paul Sutter, a professor at Stony Brook University and author of “How to Die in Space,” likened studying star life cycles to capturing snapshots of people’s lives. While it’s impossible to watch a single star’s entire lifecycle, observations of numerous stars at different stages allow experts to predict planetary deaths similar to this one.
Researchers hope Webb’s investigation of the aftermath will answer more questions about the event and provide insights into similar occurrences elsewhere.
