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

Abstract

<jats:title>ABSTRACT</jats:title> <jats:p>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.</jats:p>

The discovery and characterization of a kilometre sized asteroid inside the orbit of Venus

“…The assumed value of 0.15 is the average asteroid phase parameter determined by photometric observations of a large ensemble of asteroids regardless of spectral class (Oszkiewicz et al 2012;Vereš et al 2015). Our spectrum and the spectrum reported by others of Ayló chaxnim (Popescu et al 2020) constrains the taxonomy of Ayló chaxnim to be likely S-type (Fig. 5).…”

Tuning the Legacy Survey of Space and Time (LSST) Observing Strategy for Solar System Science

“…Granvik et al 2018). In addition, recent observational evidence and dynamical studies suggest that there are possible metastable regions in the innermost portion of the solar system where more objects on orbits similar to that of 'Ayló'chaxnim may be lurking and awaiting discovery (de la Fuente Marcos & de la Fuente Marcos 2020a; Greenstreet 2020; Popescu et al 2020;Bolin et al 2022Bolin et al , 2023Ip et al 2022;Sheppard et al 2022).…”

“…The full 802,000-object Granvik sample is available for download from https://www.mv.helsinki.fi/home/mgranvik/data/Granvik+_2018_Icarus/; the subset is selected as described in detail at https://github.com/lsst-sssc/ SSSC_test_populations_gitlfs/blob/master/MAF_TEST/granvik/Granvik% 20NEO%20Model.ipynb.42 Previously this population was referred to as the Vatira population or Vatiras(Greenstreet et al 2012) before the discovery of the first known object 'Ayló'chaxnim(Bolin et al 2020c(Bolin et al , 2022; de la Fuente Marcos & de la Fuente Marcos 2020a; Greenstreet 2020;Popescu et al 2020;Ip et al 2022). …”

Near the Edge of the Atira Orbital Realm: Short-term Dynamical Evolution of 2020 HA10 and 2020 OV1

“…This large binary asteroid may have a primary of 4.8±0.5 km in diameter (Rivera-Valentin et al 2017). Out of the 23 known Atiras (as of 2020-July-24), 15 of them have been discovered during the last decade, including the first Vatira (Q<0.718 au, Greenstreet et al 2012), 2020 AV 2 (Bolin et al 2020), that has been recently characterized, both dynamically (Greenstreet 2020; de la Fuente Marcos & de la Fuente Marcos 2020) and physically (Popescu et al 2020). The two most recent discoveries, 2020 HA 10 and 2020 OV 1 , further confirm that the Solar System inside the orbit of the Earth hosts a non-negligible fraction of dynamically interesting minor bodies (Ribeiro et al 2016).…”