UNC-Chapel Hill researchers discover the youngest transiting planet: A revelation that challenges the current understanding of how planets are formed

University of North Carolina at Chapel Hill researchers have made an exciting discovery of a 3-million-year-old planet, TIDYE-1b – on a human scale, the equivalent in age to a two-week-old baby. This newly discovered planet challenges previous theories about the speed of planet formation. While Earth took 10-20 million years to form, TIDYE-1b emerged in a mere 3 million years and orbits its star roughly every week.  

This research provides a revolutionary glimpse into the early stages of planet formation, setting a new benchmark for young planets and marking a step forward in our understanding of planetary systems beyond our own. 

“Astronomy helps us explore our place in the Universe — where we came from and where we might be going. Discovering planets like this one allows us to look back in time, catching a glimpse of planetary formation as it happens,” said Madyson Barber, lead author of the study and researcher in the department of physics and astronomy at UNC-Chapel Hill.  

The team of researchers aimed to explore how planets form and evolve, with a focus on identifying planets at various stages to better understand these processes. TIDYE-1b, the youngest known transiting planet, offers a unique window into the environment of an emerging planetary system. This discovery sheds light on potential differences between our solar system and systems hosting close-in giant planets like TIDYE-1b, providing a greater context for our own cosmic neighborhood. 

This discovery opens new research avenues, as this planet, still within its natal disk of material, allows scientists to study the formation process up close. Follow-up studies will analyze how the planet’s atmosphere compares to the surrounding disk material, providing clues about its journey to its compacted orbit. Researchers will also examine whether TIDYE-1b is still growing by accreting material or possibly losing its upper atmosphere due to the influence of its host star. 

“Planets typically form from a flat disk of dust and gas, which is why planets in our Solar System are aligned in a ‘pancake-flat’ arrangement. But here, the disk is tilted, misaligned with both the planet and its star — a surprising twist that challenges our current understanding of how planets form,” said Andrew Mann, principal investigator of the Young Worlds Laboratory and associate professor of physics and astronomy at UNC-Chapel Hill. 

The technique used to detect the planet makes this discovery especially significant. Typically, planets on the edge of their solar system this young are impossible to observe due to interference from the surrounding disk. However, the star’s disk is warped, allowing a rare observation opportunity. The research team employed a specially designed search algorithm, Notch, and refined data extraction methods from NASA’s TESS mission to detect and confirm this planet. The collaboration’s access to numerous telescopes facilitated the verification of the discovery, ensuring the signal was planetary. 

The research paper is available online in the journal Nature at: https://www.nature.com/articles/s41586-024-08123-3