[PPS07-P18] Near-Earth Asteroid Survey with Tomo-e Gozen
Keywords:solar system small bodies, near earth asteroids, surveys, CMOS camera
We have developed a wide-field mosaic CMOS camera, Tomo-e Gozen, mounted on the 105-cm Schmidt Telescope in Kiso Observatory, the University of Tokyo. Tomo-e Gozen is equipped with 84 CMOS sensors and monitors the sky of about 20 sq-degrees at 2 Hz. The total amount of the data obtained in a night is as much as 20 TB. An unique feature of Tomo-e Gozen is a continuous, video-like observation. Tomo-e Gozen is designed to detect every transient phenomena with timescale of about 1 second. The specifications of Tomoe Gozen, a high sensitivity, large field-of-view, and high frame rate, are ideal to detect fast moving objects, such as near-earth asteroids close to the Earth.
A wide-field survey with Tomo-e Gozen have started in October, 2019. A number of transient phenomena, near-earth asteroids, and space debris have been detected by dedicated data reduction pipelines. A near-earth asteroid pipeline detects every linear motion in the video data. Objects moving at 1−50"/s are successfully extracted even in crowded fields. In the operation in 2019, 6 near-earth asteroids are newly discovered. All the absolute magnitudes of the detected asteroids are fainter than 25 mag, corresponding to about 40 m in diameter assuming that the geometric albedo is 0.1. The survey with Tomo-e Gozen successfully detected small near-earth asteroids. In this presentation, the specifications of Tomo-e Gozen and the survey design are presented, as well as the algorithm to detect moving object in huge data, as much as 20 TB per day. Then, future prospects of the Tomo-e Gozen survey are discussed