Gaia Data Release 3: Distribution of Spectral Groups of Near-Earth Asteroids

Abstract

Based on the data from the third edition of the Gaia catalog, containing the reflectance spectra of asteroids, studies of near-Earth asteroids (NEAs) were carried out. The reflectance spectra of about 100 representatives of the Aten, Apollo and Amor groups were used to determine their spectral class. For 47 asteroids such an assessment was made for the first time. For convenience, the classes were grouped into broader spectral groups (according to Tholen). The distribution by spectral groups (average 60% S-group, 20% C-group, 20% others) was consistent with results obtained previously using other data from a larger sample of objects. This distribution remains similar to what is known for NEAs of different sizes. Despite the numerical predominance of group S asteroids in the NEA data sample, asteroids of primitive types (group C) are also found at very small perihelion distances, which can indirectly confirm the widespread occurrence of the phenomenon of sublimation activity of asteroids.