A recent discovery by NASA’s James Webb Space Telescope has shed new light on the fate of planets engulfed by aging stars. Contrary to previous theories, data suggests that planets do not undergo a sudden, dramatic swallowing event but instead spiral slowly inward over time.
Researchers from NSF’s NOIRLab observed a planet orbiting its host star 12,000 light-years away from Earth. The team used the telescope’s mid- and near-infrared instruments to analyze data collected since 2020. Their findings reveal that the planet was roughly Jupiter-sized and orbited closer than Mercury orbits the Sun.
Over millions of years, the planet spiraled inward, eventually brushing against the star’s outer atmosphere, triggering a runaway effect that accelerated its descent. The encounter also blew gas outward from the star’s surface, creating a faint halo that persisted in the infrared long after the planet’s demise.
Further analysis by Webb’s Near-Infrared Spectrograph revealed a hot, molecular gas disk surrounding the star, containing carbon monoxide and other compounds commonly found in regions where planets are born. This unexpected discovery provides fresh clues about what happens to planets after they disappear into stars.
The research team hopes this event will serve as a reference point for studying similar phenomena in our own solar system. As the Sun approaches its final stages in about five to seven billion years, scientists expect more events like ZTF SLRN-2020 to be discovered.
Source: https://www.earth.com/news/first-ever-recorded-planetary-engulfment-event-captured-by-webb