Astronomers have discovered a new feature in the distribution of exoplanets, which they’ve dubbed the “Neptunian Ridge.” This finding sheds light on the complex dynamics within the Neptunian Desert, a region with a scarcity of hot Neptunes, and the Neptunian Savanna, where these planets are more commonly found.
The team led by an international group including members from the University of Geneva, The NCCR PlanetS, and the Centro de Astrobiología (CAB) analyzed data from NASA’s Kepler mission to identify the feature. They found that Neptune-sized planets are surprisingly scarce in the Neptunian Desert, a region thought to be harsh due to intense stellar radiation stripping away the atmospheres of these planets.
Beyond this “desert” lies the “Neptunian Savanna,” where conditions allow Neptune-sized planets to maintain their gaseous envelopes and are more populous. The researchers found an unexpected concentration of Neptune-sized planets at the edge of the Neptunian Desert, which they’ve named the “Neptunian Ridge.”
The discovery was made possible by analyzing data from NASA’s Kepler mission, corrected for observational biases using advanced statistical techniques. The researchers meticulously mapped the period-radius space of these exoplanets, revealing distinct regions that define the Neptunian landscape.
Understanding the Neptunian Ridge and its connection to the Neptunian Desert and Savanna provides valuable insights into the dynamic processes that influence the formation and evolution of close-in exoplanets. The discovery is published in the journal Astronomy & Astrophysics.
Source: https://phys.org/news/2024-09-astronomers-feature-exoplanet-neptunian-savanna.html