“All of the elements that would make up a rocky planet are exactly the elements that are enhanced on Kronos,” Oh said. “And the volatile elements are not enhanced, so that provides a strong argument for a planet engulfment scenario, instead of something else.”
The study also provides new insight into stellar formation and exoplanets.
“At the moment, we are still at the stage of piecing together different observations to determine how and when exoplanets form,” said Jessie Christiansen, an astronomer at the NASA Exoplanet Science Institute at the California Institute of Technology who was not involved in the research.
“It’s difficult to directly observe planet formation around young stars — they are typically shrouded in dust, and the stars themselves are very active, which makes it hard to disentangle any signals from the planets,” Christiansen said. “So we have to infer what we can from the limited information we have. If borne out, this new window onto the masses and compositions of the material in the early stages of planetary systems may provide crucial constraints for planet formation theories.”