TOI-1710 b: a super-Neptune on a retrograde, strongly misaligned orbit challenges planet migration theories

Star system: TOI 1710 | Distance from the Sun: 265 light years

TOI-1710 b is a super-Neptune planet orbiting a cool star, but unlike most planets, its orbit is strongly misaligned and retrograde, meaning it moves in the opposite direction to the star's rotation. This was determined using high-precision radial velocity measurements during a transit, which revealed a large angle between the planet's orbital plane and the star's spin axis.

The planet's orbit is wide enough that tidal forces have not altered its original tilt, making it a valuable case for studying how planetary systems form and evolve. The strong misalignment suggests that TOI-1710 b likely underwent high-eccentricity migration, possibly due to interactions with other planets in the system. This challenges previous ideas that such migration is rare for planets of this size and orbit. The lack of a nearby stellar companion points to planet-planet interactions, such as scattering and Kozai-Lidov oscillations, as the cause of the planet's current orbit.

These findings provide new evidence that even low-density, Neptune-sized planets can experience dramatic changes in their orbits, reshaping our understanding of planetary migration and system evolution.

Key findings
- TOI-1710 b is a super-Neptune on a retrograde, strongly misaligned orbit
- The planet's orbit is unaffected by tidal forces, preserving its original tilt
- High-eccentricity migration likely caused the misalignment
- No close stellar companion detected, pointing to planet-planet interactions
- Results challenge previous views on migration of Neptune-sized planets

Scientific study

A tidally detached super Neptune on a strongly misaligned retrograde orbit (external link)