We present an analysis of a stellar occultation event caused by a near-Earth asteroid (98943) 2001 CC21, an upcoming flyby target in the Hayabusa2 extended mission, on March 5, 2023. To accurately determine the asteroid's shape from diffraction-affected light curves, we developed a novel data reduction technique named the Diffracted Occultation's United Simulator for Highly Informative Transient Explorations (DOUSHITE). Using DOUSHITE-generated synthetic models, we derived constraints on (98943) 2001 CC21's shadow shape from the single-chord occultation data. Our results suggest a significant elongation of the shadow with an axis ratio of b/a=0.37±0.09. This shape can be crucial for planning Hayabusa2's high-speed flyby to optimise the limited imaging opportunities.
@article{arxiv.2407.19836,
title = {Diffraction modelling of a 2023 March 5 stellar occultation by subkilometer-sized asteroid (98943) 2001 CC21},
author = {Ko Arimatsu and Fumi Yoshida and Tsutomu Hayamizu and Miyoshi Ida and George L Hashimoto and Takashi Abe and Hiroshi Akitaya and Akari Aratani and Hidekazu Fukuda and Yasuhide Fujita and Takao Fujiwara and Toshihiro Horikawa and Tamio Iihoshi and Kazuyoshi Imamura and Ryo Imazawa and Hisashi Kasebe and Ryosuke Kawasaki and Hiroshi Kishimoto and Kazuhisa Mishima and Machiko Miyachi and Masanori Mizutani and Maya Nakajima and Hiroyoshi Nakatani and Kazuhiko Okamura and Misaki Okanobu and Masataka Okuda and Yuji Suzuki and Naoto Tatsumi and Masafumi Uno and Hidehito Yamamura and Mikoto Yasue and Hideki Yoshihara and Masatoshi Hirabayashi and Makoto Yoshikawa},
journal= {arXiv preprint arXiv:2407.19836},
year = {2024}
}