Physical characterization of 2020 AV2, the first known asteroid orbiting inside Venus orbit.

The first known asteroid with the orbit inside that of Venus is 2020 AV₂. This may be the largest member of a new population of small bodies with the aphelion smaller than 0.718 au, called Vatiras. The surface of 2020 AV₂ is being constantly modified by the high temperature, by the strong solar wind irradiation that characterizes the innermost region of the Solar system, and by high-energy micrometeorite impacts. The study of its physical properties represents an extreme test-case for the science of near-Earth asteroids. Here, we report spectroscopic observations of 2020 AV₂ in the 0.5–1.5-μm wavelength interval. These were performed with the Nordic Optical Telescope and the William Herschel Telescope. Based on the obtained spectra, we classify 2020 AV₂ as a Sa-type asteroid. We estimate the diameter of this Vatira to be |$1.50_{-0.65}^{+1.10}$| km by considering the average albedo of A-type and S-complex asteroids (⁠|$p_V=0.23_{-0.08}^{+0.11}$|⁠), and the absolute magnitude (H  = 16.40 ± 0.78 mag). The wide spectral band around 1 μm shows the signature of an olivine-rich composition. The estimated band centre BIC  = 1.08 ± 0.02 μm corresponds to a ferroan olivine mineralogy similar to that of brachinite meteorites. [ABSTRACT FROM AUTHOR]