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

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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+1.10−0.65 km by considering the average albedo of A-type and S-complex asteroids (⁠pV=0.23+0.11−0.08⁠), 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.
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society Published by Oxford University Press on behalf of the Royal Astronomical Society
Akhlaghi M., Ichikawa T., 2015, ApJS, 220, 1 Bacci P., et al., 2020, Minor Planet Electronic Circulars, 2020-A99 Binzel R. P., et al., 2010, Nature, 463, 331 Binzel R. P., et al., 2019, Icarus, 324, 41 Bott N., Doressoundiram A., Zambon F., Carli C., Guzzetta L., Perna D., Capaccioni F., 2019, Journal of Geophysical Research (Planets), 124, 2326 Burbine T. H., Meibom A., Binzel R. P., 1996, Meteoritics and Planetary Science, 31, 607 Burbine T. H., Buchanan P. C., Dolkar T., Binzel R. P., 2009, Meteoritics and Planetary Science, 44, 1331 Burns R. G., 1993, Mineralogical Applications of Crystal Field Theory Bus S. J., Binzel R. P., 2002, Icarus, 158, 146 Carry B., Solano E., Eggl S., DeMeo F. E., 2016, Icarus, 268, 340 Cloutis E. A., Gaffey M. J., Jackowski T. L., Reed K. L., 1986, J. Geophys. Res., 91, 11,641 DeMeo F. E., Binzel R. P., Slivan S. M., Bus S. J., 2009, Icarus, 202, 160 DeMeo F. E., Alexander C. M. O., Walsh K. J., Chapman C. R., Binzel R. P., 2015, The Compositional Structure of the Asteroid Belt. pp 13–41, doi:10.2458/azu_uapress_9780816532131-ch002 DeMeo F. E., Polishook D., Carry B., Burt B. J., Hsieh H. H., Binzel R. P., Moskovitz N. A., Burbine T. H., 2019, Icarus, 322, 13 Delbo M., et al., 2014, Nature, 508, 233 Devogèle M., et al., 2019, AJ, 158, 196 Dunn T. L., McCoy T. J., Sunshine J. M., McSween H. Y., 2010, Icarus, 208, 789 Eaton J. W., Bateman D., Hauberg S., Wehbring R., 2018, GNU Octave version 4.4.0 manual: a high-level interactive language for numerical computations. Gaffey M. J., Bell J. F., Brown R. H., Burbine T. H., Piatek J. L., Reed K. L., Chaky D. A., 1993, Icarus, 106, 573 Giorgini J. D., 2015, in IAU General Assembly. p. 2256293 Granvik M., et al., 2016, Nature, 530, 303 Granvik M., et al., 2018, Icarus, 312, 181 Greenstreet S., 2020, MNRAS, 493, L129 Greenstreet S., Ngo H., Gladman B., 2012, Icarus, 217, 355 Hasegawa S., Hiroi T., Ohtsuka K., Ishiguro M., Kuroda D., Ito T., Sasaki S., 2019, PASJ, 71, 103 Hutchison R., 2004, Meteorites King T. V. V., Ridley W. I., 1987, J. Geophys. Res., 92, 11457 Kozai Y., 1962, AJ, 67, 591 Lidov M. L., 1962, Planet. Space Sci., 9, 719 Mainzer A., et al., 2011, ApJ, 741, 90 Milliken R. E., Hiroi T., Patterson W., 2016, in Lunar and Planetary Science Conference. p. 2058 Mittlefehldt D. W., Bogard D. D., Berkley J. L., Garrison D. H., 2003, Meteoritics and Planetary Science, 38, 1601 Perna D., et al., 2018, Planet. Space Sci., 157, 82 Pieters C. M., Hiroi T., 2004, in Mackwell S., Stansbery E., eds, Lunar and Planetary Inst. Technical Report Vol. 35, Lunar and Planetary Science Conference. Popescu M., et al., 2016, A&A, 591, A115 Popescu M., et al., 2018a, MNRAS, 477, 2786 Popescu M., Licandro J., Carvano J. M., Stoicescu R., de León J., Morate D., Boaca I. L., Cristescu C. P., 2018b, A&A, 617, A12 Popescu M., et al., 2019, A&A, 627, A124 Pravec P., Harris A. W., 2007, Icarus, 190, 250 Reddy V., Nathues A., Gaffey M. J., Schaeff S., 2011, Planet. Space Sci., 59, 772 Ryan E. L., Woodward C. E., 2010, AJ, 140, 933 Sánchez J. A., Reddy V., Nathues A., Cloutis E. A., Mann P., Hiesinger H., 2012, Icarus, 220, 36 Sánchez J. A., et al., 2014, Icarus, 228, 288 Sharma I., Jenkins J. T., Burns J. A., 2006, Icarus, 183, 312 Stenborg G., Stauffer J. R., Howard R. A., 2018, ApJ, 868, 74 Sunshine J. M., Bus S. J., Corrigan C. M., McCoy T. J., Burbine T. H., 2007, Meteoritics and Planetary Science, 42, 155 Tatsumi E., et al., 2018, Icarus, 311, 175 Tody D., 1986, The IRAF Data Reduction and Analysis System. p. 733, doi:10.1117/12.968154 Vernazza P., Binzel R. P., Thomas C. A., DeMeo F. E., Bus S. J., Rivkin A. S., Tokunaga A. T., 2008, Nature, 454, 858 Vokrouhlický D., Bottke W. F., Chesley S. R., Scheeres D. J., Statler T. S., 2015, The Yarkovsky and YORP Effects. pp 509–531, doi:10.2458/azu_uapress_9780816532131-ch027 de León J., Duffard R., Licandro J., Lazzaro D., 2004, A&A, 422, L59 de León J., Licandro J., Serra-Ricart M., Pinilla-Alonso N., Campins H., 2010, A&A, 517, A23 de la Fuente Marcos C., de la Fuente Marcos R., 2019a, Research Notes of the American Astronomical Society, 3, 106 de la Fuente Marcos C., de la Fuente Marcos R., 2019b, MNRAS, 487, 2742 de la Fuente Marcos C., de la Fuente Marcos R., 2020, MNRAS, 494, L6 von Zeipel H., 1910, Astronomische Nachrichten, 183, 345