NASA’s James Webb Space Telescope has offered fresh insights into a rare planetary engulfment event first reported in 2020. The object in question, ZTF SLRN-2020, was initially thought to have been consumed when its host star expanded into a red giant.
Contrary to the original theory, new data from Webb suggest the star did not expand to swallow the planet. Instead, the planet’s orbit decayed gradually over time, pulling it closer to the star until it was eventually consumed.
Researchers found a hot accretion disc and an expanding cloud of cooler dust around the star. These findings indicate the planet likely lost its outer layers during the plunge and created visible remnants from the resulting heat and pressure.
Astronomers believe gravitational interactions with the host star caused the planet to slowly spiral inward. Once close enough, it began grazing the stellar atmosphere, accelerating its descent and stripping away its gaseous layers.
Although Webb’s observations offer strong clues, the researchers admit that the precise sequence of events remains unconfirmed. Scientists rely on computer models to simulate such scenarios, as experimental replication is not feasible.
None of the planets in our solar system are currently close enough to the sun to face a similar orbital decay. However, in about five billion years, the sun is expected to enter its red giant phase, possibly engulfing Mercury, Venus, and even Earth.
According to the study, planets may be more likely to meet their end through gradual orbital decay rather than sudden engulfment by an expanding star. The findings provide valuable data for understanding long-term planetary evolution.