Astronomers have captured an unprecedented celestial event involving ZTF SLRN-2020, a star located approximately 12,000 light-years from Earth, which appeared to engulf a Jupiter-sized planet. At first, astronomers thought it was a straightforward case of planet-eating. Recent observations from NASA’s James Webb Space Telescope (JWST) tell a very different story. This pioneering identification portrays the complex relationship between stars and their planets. It opens up new lines of inquiry into the life cycles of celestial bodies.
This event marks the dawning of a new age in astronomy. In fact, it probably features the first example of a planetary engulfment observed in real-time. That star in particular is becoming an old star, moving into the last phases of its life and becoming a red giant. As the star burns through its hydrogen supply, it swells massively. At first this expansion seems to warrant the assumption that it was responsible for the observed brightening episod.
Unraveling the Mystery
At first, astronomers believed the star was in the process of exploding. They suspected this expansion was responsible for the violent changes in the light emitted from ZTF SLRN-2020. With JWST’s unprecedented power came unprecedented clarity, and new understanding dispelled their original conclusions. Instead of the star swallowing the planet whole, it seems that the very strong gravitational forces in this case pulled the planet in much tighter orbits.
This Jupiter-sized planet had been orbiting in an extremely tight orbit around its host star — tighter than Mercury orbits our own Sun. This close encounter intensified fears for the planet’s future as its star moved through the first stages of its red giant evolution. The inferences from the observations indicate that tidal interactions were central to the planet’s fate. Increasing gravitational forces from two other celestial bodies shifted that dynamic, eventually tearing the planet apart.
“It’s not every day that we find these kinds of events.” – Ryan Lau, an assistant astronomer at the National Science Foundation National Optical-Infrared Astronomy Research Laboratory in Tucson, Arizona
The Process of Consumption
Given the consumption method of ZTF SLRN-2020’s planet, this all probably happened over a few short months. The JWST data shows that over time tidal interactions gradually eroded the planet’s orbit. As a consequence, the planet plummeted inward and was ultimately devoured by its star. This short sequence of events serves as a testament to the ever-changing, violent nature of celestial bodies in our solar system and their interactions.
This finding not only upends previously held scientific wisdom, but shows how poorly understood these kinds of phenomena are. The impact of this event extends far beyond simply watching it. It inspires us to query further and probe deeper — how frequent might such events be across the galaxy.
“We should be finding way more of these.” – Ryan Lau, an assistant astronomer at the National Science Foundation National Optical-Infrared Astronomy Research Laboratory in Tucson, Arizona
Future Discoveries Await
The opening of the Vera C. Rubin Observatory is expected to enhance astronomers’ ability to detect similar events in the future. As technology improves, researchers will find more examples of planetary engulfments. They think they’ll find a host of other cosmic phenomena that haven’t been seen before.
Regardless of the uncertainty, the recent discoveries surrounding ZTF SLRN-2020 are intriguing and revolutionary. Yet they serve to remind us of the challenges that are always present in astronomical investigations. By confusing first impressions, this special program inspires an ongoing quest to discover knowledge from above while looking to the universe.
