Astronomers have spotted a remarkable event where a star in the main sequence appears to have swallowed a planet. Reports from Universe Today first brought attention to this unusual occurrence.
The discovery began when researchers observed an optical transition associated with the intermediate-luminosity event named ZTF SLRN-2020. Experts classify this as an astrophysical phenomenon where a star shines brighter than a familiar, steady state but remains far dimmer than a supernova. Such events are rare, and scientists still have many questions about their causes. One prevailing idea is that the brightening results from a planet being absorbed by the star. A key distinction in this case is that the host star belongs to the main sequence, meaning it is relatively mature. By contrast, younger stars can host planets that move chaotically and are more prone to destabilized orbits and collisions.
Following a fresh analysis of past observations, astronomer Noam Socker proposes that the planet did not simply plunge into the photosphere and vanish. Instead, he suggests the planet underwent a sequence of transformations as it drew nearer to the star. As the planet approached, it heated up and its outer layers ionized into plasma. This transformation triggered a cascade of electrical and magnetic effects, and jets appeared to erupt from the planet. Yet the momentum and velocity of these jets were not sufficient to overcome the star’s strong gravity, causing much of the material to fall back toward the stellar surface.
Before this material was fully absorbed, parts of it could form an accretion disk around the star. This disk would gradually feed material onto the stellar surface, while the overall interactions released enormous amounts of energy that astronomers could measure across the spectrum. The event offers a compelling glimpse into how planetary material interacts with mature stars and how such interactions manifest as bright, transient signals in the night sky.
Additionally, researchers are exploring how these processes influence the surrounding environment of the star, including potential effects on any residual debris and magnetic activity. The case of ZTF SLRN-2020 provides a rare laboratory for studying star-planet interactions in a regime that blends planetary science with stellar physics. It also highlights the importance of long-term monitoring and rapid follow-up observations to capture the full evolution of such dramatic encounters.
In the broader context, this kind of event underscores the dynamic nature of planetary systems and the variety of outcomes that can occur when a planet and its star engage in a gravitational embrace. As observations continue and models improve, scientists expect to refine the understanding of how common these planet-star swallowing episodes are and what they reveal about the life cycles of solar-type stars. The ongoing research holds promise for shedding light on the fate of worlds that orbit aging stars and on the fate of planetary systems as a whole.