The OASES project: exploring the outer Solar System through stellar occultation with amateur-class telescopes.

The exploration of kilometre-sized trans-Neptunian objects (TNOs) is one of the ultimate goals in the search for the origin and evolution of the Solar System. However, such exploration is challenging because these small bodies are too faint to be directly detected. One potential avenue for detecting and investigating small and faint TNOs is the monitoring of stellar occultation events. This paper reviews the concept and methodology of monitoring observations of stellar occultations by small, unidentified TNOs, focusing on our observational programme, Organized Autotelescopes for Serendipitous Event Survey (OASES). OASES aims to detect and investigate stellar occultations by unidentified TNOs using multiple amateur-sized telescopes equipped with commercial complementary metal-oxide-semiconductor (CMOS) cameras. Through the monitoring observations conducted so far, OASES has found one possible occultation event by a kilometre-sized TNO. The paper also discusses future developments of the OASES project and deliberates on the potential of movie observations in expanding the frontiers of outer Solar System research.This article is part of the theme issue 'Major advances in planetary sciences thanks to stellar occultations'.