A Cold Clue in the Sky: Using Infrared Light to Hunt for Planet Nine
Chen et al. searched AKARI infrared data for Planet Nine by looking for heat rather than sunlight. After filtering millions of sources for movement and known objects, they identified two promising candidates. These objects matched expected brightness and motion patterns, but further observations are needed to confirm if either one is truly Planet Nine.
A Deep Dive into the Solar System’s Outer Frontier: Pan-STARRS Hunts for Distant Worlds
Holman et al. used Pan-STARRS1 data to search for distant solar system objects, identifying 692 candidates, including 109 new ones. They developed a novel detection method using synthetic populations and machine learning. Although Planet Nine was not found, the study narrowed its possible location to the galactic plane and demonstrated a powerful framework for future surveys.
Hunting Planet Nine: A Far-Infrared Search with IRAS and AKARI
Terry Long Phan and collaborators searched for Planet Nine using infrared data from the IRAS and AKARI missions. They identified one strong candidate that appears to move across the sky over 23 years. However, more observations, such as with the DECam, are needed to confirm if it is truly Planet Nine.
Investigating the Orbit of a Potential 'Planet X' in the Outer Solar System
Siraj and colleagues explore the possibility of a hidden "Planet X" in the outer Solar System by analyzing clustering patterns in the orbits of distant trans-Neptunian objects (TNOs). They find statistically significant clustering that may indicate the gravitational influence of an unseen planet with around 4.4 Earth masses, located approximately 290 AU from the Sun. Their simulations suggest that this hypothetical planet could be detected by future surveys, especially the upcoming Vera C. Rubin Observatory, which could confirm the existence of Planet X.