Two young giant planets discovered with the longest orbital periods for their class

Star system: HD 114082 | Distance from the Sun: 310 light years

Astronomers have identified two young, large-radius planets orbiting the F-type star HD 114082, marking them as the longest-period young transiting exoplanets currently known. These planets, designated b and c, were detected through a collaborative effort using data from multiple space and ground-based telescopes, including TESS, the Next-Generation Transit Survey (NGTS), the Characterising Exoplanet Satellite (CHEOPS), and the Antarctic Search for Transiting ExoPlanets (ASTEP+). Their discovery provides a unique opportunity to study giant planet formation and evolution within a system that still contains a debris disk.

The orbital characteristics of these planets are distinct, with planet b completing an orbit in approximately 225 days, while planet c follows at a slightly wider distance. Detailed modeling of both photometric transit data and radial velocity measurements, supported by N-body dynamical simulations, helped constrain their physical parameters. Planet b has a radius of roughly 1.05 times that of Jupiter, while planet c is larger, with a radius of about 1.36 times that of Jupiter. Both are considered moderate-to-low-mass gas giants.

The researchers also examined the surrounding debris disk, finding that its structure is best explained by the presence of two distinct dust components. Given the orbital configuration of the planets — which appear to be in nearly resonant, coplanar, and circular orbits — the study suggests they may have formed either in place or further out beyond the snow line before migrating inward. Their presence and movement have likely played a significant role in shaping the architecture of the debris disk observed around the host star.

Key findings
- Discovery of two young giant planets, HD 114082 b and c, which hold the record for the longest orbital periods among known young transiting exoplanets.
- Planet b has an orbital period of approximately 225 days, and planet c orbits further out at roughly 0.99 astronomical units.
- Both planets are puffy gas giants with radii larger than Jupiter, orbiting within a system that still retains a debris disk.
- The planets appear to be in stable, near-resonant orbits, suggesting a history of inward migration that has influenced the system's dust disk.

Scientific study

The Longest-period Young Transiting Exoplanets—A Duo of Puffy Giants inside a Debris Disk (external link)