Projects

Organized Autotelescopes for Serendipitous Event Survey (OASES) is a project that monitors many stars simultaneously from multiple sites with optical video observations, aiming to detect stellar occultations by unknown small bodies such as trans-Neptunian objects. Using wide-field video observation systems with 28 cm aperture telescopes, OASES can capture extremely rare phenomena that occur on timescales too short to be detected by conventional observations. In 2019, OASES monitoring observations on Miyako Island achieved the world’s first detection of a candidate stellar occultation by a kilometre-sized trans-Neptunian object. For details, see the NAOJ press release or the paper (Arimatsu et al. Nature Astronomy, 3, 301, 2019).

Planetary ObservatioN Camera for Optical Transient Surveys (PONCOTS) is an optical observation project that captures short-lived transient phenomena on specific celestial bodies with high time resolution and in multiple wavelengths simultaneously. Using a video observation system with a 28 cm aperture telescope capable of observing in up to three wavelengths at once, PONCOTS observes the flashes produced when tiny bodies from the outer solar system enter Jupiter’s atmosphere (Jovian impact flashes), advancing our understanding of the impact rate of such bodies on Jupiter and the properties of the flashes. In 2021, PONCOTS monitoring of Jupiter achieved the world’s first simultaneous three-wavelength observation of a Jovian impact flash. For details, see the Kyoto University press release (in Japanese) or the paper (Arimatsu et al. Astrophysical Journal Letters, 933, L5, 2022).