Bibcode
Popescu, Marcel M.; Tatsumi, Eri; Licandro, Javier; Alarcon, Miguel R.; Rodríguez Rodríguez, Javier; Serra-Ricart, Miquel; de León, Julia; Fernandez Martin, Joaquín; Morate, David; Simion, Gabriel N.; Dumitru, Bogdan Alexandru; Berteşteanu, Daniel Nicolae; Prodan, George Pantelimon; Hirabayashi, Masatoshi
Referencia bibliográfica
The Planetary Science Journal
Fecha de publicación:
2
2025
Número de citas
0
Número de citas referidas
0
Descripción
The near-Earth asteroid (98943) Torifune, previously designated 2001 CC21, is the flyby target of the Hayabusa2 extended mission, nicknamed Hayabusa2# (Small Hazardous Asteroid Reconnaissance Probe (SHARP)). The ground-based telescope observations offer a key science input for the mission's scientific investigation. During 2022–2024, this asteroid was at visible apparent magnitudes brighter than 18.5, allowing for a detailed characterization using ground-based telescope observations. We determined its rotation period P = 5.021516 ± 0.000106 hr and its absolute magnitude H = 18.78 ± 0.14. The large number of light curves allows us to estimate its axis ratio, its convex shape, and its pole orientation, λ = 301∘ ± 35∘, , and ϵ = 5∘ ± 3∘, respectively, which indicate a prograde rotation. We report the semiaxis of the equivalent ellipsoid, a = 0.42 km, b = 0.16 km, and c = 0.17 ± 0.03 km. Consequently, the volume-equivalent diameter is Deq = 0.44 ± 0.06 km. Using observations conducted simultaneously with four broadband filters, we determined (g ‑ r) = 0.663 ± 0.022 mag, (r ‑ i) = 0.177 ± 0.012 mag, and (i ‑ zs) = ‑0.061 ± 0.032 mag. Additionally, we found that Torifune exhibits no detectable large-scale heterogeneity. We classified the object using a high signal-to-noise ratio spectrum (over the visible and near-infrared region) as Sq-type in the Bus–DeMeo taxonomy. We estimate a mineralogy similar to LL/L ordinary chondrites, with an ol/(ol+px) = 0.60, a Fa content of 28.5 mol%, and a Fs content of 23.4 mol%. The spectral data indicate a surface affected by moderate space weathering effects. *Based on observations made with the Two-meter Twin Telescope (TTT) and the Telescopio Carlos Sanchez (TCS) in the Spanish Observatorio del Teide, the Gran Telescopio Canarias (GTC) telescope and the Isaac Newton Telescope (INT) in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, and the NASA Infrared Telescope Facility (NASA IRTF) at the Maunakea Observatory in Hawaii.