[P-PS04] Small Solar System Bodies: A New Insight from Hayabusa2, OSIRIS-REx and Other Space Missions

[PPS04-P02] Characteristics of high-albedo C-complex asteroids

*Sunao Hasegawa¹, Toshihiro Kasuga², Fumihiko Usui^1,3, Kuroda Daisuke⁴ (1.Japan Aerospace Exploration Agency, 2.National Astronomical Observatory of Japan, 3.Kobe University, 4.Kyoto University)

Almost C-complex asteroids have albedo values lower than 0.1, but there are some high-albedo C-complex asteroids with albedo values exceeding 0.1.
To clarify the nature and origin of high-albedo C-complex asteroids, we conducted spectroscopic observations of the asteroids in at visible and near-infrared wavelength regions.
The Bus B-, C-, and Ch-type asteroids with high-albedo values, which are subclasses of the Bus C-complex asteroids, are classified as DeMeo C-type asteroids with concave curvature, B-, Xn-, and K-type asteroids.
Analogue material such as CV/CK chondrites, enstatite chondrites/achondrites, and salts related with these spectral types of high-albedo asteroids are thought to be composed of minerals and material exposed to high temperatures.
A comparison of the results obtained in this study with the SDSS photometric data suggests the following three possibilities.
High-albedo C-complex asteroids that do not belong to any families are likely to be impact-metamorphosed carbonaceous chondrites, CV/CK chondrites, or enstatite chondrites/achondrites.
The high-albedo C-complex asteroids in other C-complex families were likely sourced by impact heating.
Salts may have occurred in the parent bodies of 24 Themis and 10 Hygiea, as well as 2 Pallas.