July 3, 2024A New Horizon for the Kuiper Belt: Subaru Telescope's Wide-Field Observations

The Subaru Telescope's wide and deep imaging observations are contributing information to the New Horizons spacecraft as it moves through the outer Solar System. By applying a unique analysis method to images of Kuiper Belt objects taken by the Subaru Telescope's ultra-wide-field camera, objects that have the potential to extend the Kuiper Belt region have been discovered.

What lies beyond the known planets of our solar system? Beyond Neptune, there is the Kuiper Belt, a ring-shaped region of asteroids and other small objects. The area from the Kuiper Belt to the Oort Cloud is called the "outer solar system," but our knowledge is still limited to the regions closer to the Sun.

"Looking outside of the solar system, a typical planetary disk extends about 100 astronomical units [AU] from the host star [100 times the distance between the Earth and the Sun], and the Kuiper Belt, which is estimated to extend about 50 AU, is very compact. Based on this comparison, we think that the primordial solar nebula, from which the Solar System was born, may have extended further out than the present-day Kuiper Belt," said Fumi Yoshida, from the Industrial Medical University of Japan’s Center for Planetary Exploration Research, Chiba Institute of Technology, who led the research.

Read the full story on the Subaru Telescope website.

An example of detection by JAXA's Moving Object Detection System. Moving objects are detected from 32 images of the same field taken at regular time intervals (the images in the orange frames in the above figure). Assuming the velocity range of Kuiper Belt objects, each image is shifted slightly in any direction and then stacked. The green, light blue, and black framed images are the result of stacking 2 images each, 8 images each, and 32 images, respectively. If there is a light source in the center of a single image as well as each of the overlapping images, it is considered a real object. (Credit: JAXA)