Spectral type and geometric albedo of (98943) 2001 CC21, the Hayabusa2# mission target

• DOI: 10.5281/zenodo.7993012
• Publication Date: 2023-06-12
• Authors: Jooyeon Geem; Masateru Ishiguro; Mikael Granvik; Hiroyuki Naito; Hiroshi Akitaya; Tomohiko Sekiguchi; Sunao Hasegawa; Daisuke Kuroda; Tatsuharu Oono; Yoonsoo P Bach; Sunho Jin; Ryo Imazawa; Koji S Kawabata; Seiko Takagi; Makoto Yoshikawa; Anlaug A Djupvik; Julie Thiim Gadeberg; Tapio Pursimo; Oliver Durfeldt P...; Jeppe Sinkbaek Th...; Zuri Gray
• Keywords: Earth and Planetary Astrophysics (astro-ph.EP); (98943) 2001 CC21 --- techniques: polarimetric --- techniques: spectroscopic; Techniques: polarimetric; Techniques: spectroscopic; FOS: Physical sciences; Astronomy, Space science; individual: (98943) 2001 CC [Minor planets, asteroids]; (98943) 2001 CC21 --- techniques: polarimetric --- techniques: spectroscopic; minor planets, asteroids: individual: (98943) 2001 CC21; polarimetric [Techniques]; spectroscopic [Techniques]; Astrophysics - Earth and Planetary Astrophysics

ABSTRACT We conducted optical polarimetry and near-infrared spectroscopy of Japan Aerospace Exploration Agency (JAXA)’s Hayabusa2# mission target, (98943) 2001 CC21, in early 2023. Our new observations indicate that this asteroid has a polarimetric inversion angle of ∼20°, absorption bands around 0.9 and 1.9 μm, and a geometric albedo of 0.23 ± 0.04. All these features are consistent with those of S types but inconsistent with L types. Based on this evidence, we conclude that JAXA’s Hayabusa2# spacecraft will explore an S-type asteroid (more specifically, an L or LL chondrite-like object) with albedo and size (0.44–0.53 km when we assume the absolute magnitude of 18.8) similar to (25143) Itokawa.