TOI-672 b is confirmed as a hot super-Neptune, shedding light on the Neptunian desert around red dwarfs

The Neptunian desert is a region where Neptune-sized planets are rare at short orbital periods, likely due to intense starlight stripping away their atmospheres or changes in their orbits. Understanding this desert helps scientists learn how planets evolve, especially around different types of stars. In this study, astronomers confirmed the existence of TOI-672 b, a massive super-Neptune orbiting a red dwarf star, using data from TESS, ground-based telescopes, and precise measurements from the NIRPS and HARPS spectrographs.

TOI-672 b has an orbital period of 3.63 days, a radius about 5.3 times that of Earth, and a mass about 51 times Earth's. This places it within the so-called Neptunian ridge, a group of planets found at the edge of the Neptunian desert. The researchers compared the boundaries of the desert for planets around Sun-like stars and red dwarfs, finding that the edge shifts slightly inward for red dwarfs, but not as much as some theories predict. They also found no evidence for additional planets in the system. These results help refine our understanding of how planetary systems form and evolve around different types of stars.

Key findings
- TOI-672 b is a hot super-Neptune confirmed around a red dwarf star
- The planet has a 3.63-day orbit, a radius of 5.3 Earth radii, and a mass of 51 Earth masses
- TOI-672 b sits at the edge of the Neptunian desert, in the Neptunian ridge
- The desert boundary for red dwarfs is slightly closer to the star than for Sun-like stars
- The shift in the desert boundary is smaller than predicted by some models, and no other planets were found in the system

Scientific study

Confirmation of the hot super-Neptune TOI-672 b with NIRPS and HARPS and Insights into the Neptunian desert around M dwarfs (external link)