The detection of a giant planet transiting a very young star is reported in Nature. The results indicate that this is the youngest transiting planet found to date.
Scientists had already discovered more than a dozen transiting planets (planets that pass between a star and an observer like Earth) around stars aged 10 to 40 million years.
However, even younger transiting planets had not been detected; this may be due to the planets not having fully formed yet, or because our view of these planets is blocked by a residual protoplanetary disk (the dense ring of gas and dust surrounding a newly formed star from which planets form).
Madyson Barber and colleagues analyzed data from NASA’s Transiting Exoplanet Survey Satellite and observed a young star (3 million years old), IRAS 04125+2902, which lies relatively close to Earth (160 parsecs).
The outer protoplanetary disk surrounding this star is misaligned and appears nearly face-on, as opposed to edge-on, while it has an inner disk that is depleted; this combination of characteristics allowed the observation of the protoplanet transiting IRAS 04125+2902 b.
This planet has an orbital period of 8.83 days, a radius 10.7 times that of Earth, and about 30% of Jupiter’s mass. The authors suggest that it may be a precursor to the super-Earth and sub-Neptune planets often found orbiting main-sequence stars.
Given the young age of this star and planet, the rare disk misalignment, and the relative proximity to Earth, the authors suggest that this system may be a valuable target for studying the early stages of planet formation.
