The Astronomical Journal, 159:47 (13pp), 2020 February https://doi.org/10.3847/1538-3881/ab4e1b © 2020. The American Astronomical Society. All rights reserved. A Fireball and Potentially Hazardous Binary Near-Earth Asteroid (164121) 2003 YT1 Toshihiro Kasuga1,2 , Mikiya Sato3, Masayoshi Ueda3, Yasunori Fujiwara3, Chie Tsuchiya1, and Jun-ichi Watanabe1 1 National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan;
[email protected] 2 Department of Physics, Faculty of Science, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto 603-8555, Japan 3 The Nippon Meteor Society, Japan Received 2019 August 5; revised 2019 October 10; accepted 2019 October 13; published 2020 January 13 Abstract We present a fireball detected in the night sky over Kyoto, Japan on UT 2017 April 28 at 15hms 58 19 by the SonotaCo Network. The absolute visual magnitude is Mv=−4.10±0.42 mag. Luminous light curves obtain a meteoroid mass of m=29±1 g, corresponding to the size of as=2.7±0.1 cm. Orbital similarity assessed by D-criterions (see DSH=0.0079) has identified a likely parent, the binary near-Earth asteroid (164121) 2003 YT1. The suggested binary formation process is a Yarkovsky–O’Keefe–Radzievskii–Paddack-driven rotational disintegration. The asynchronous state indicates the age of <104 yr, near or shorter than the upper limit to meteoroid stream lifetime. We examine potential dust production mechanisms for the asteroid, including rotational instability, resurfacing, impact, photoionization, radiation pressure sweeping, thermal fracture, and sublimation of ice. We find some of them capable of producing the meteoroid-scale particles.