Photometry and model of near-Earth asteroid 2022 AB from one apparition

<p>This presentation will show results of the observing campaign for the very small, super-fast rotating NEA, 2022 AB. It is a follow-up of our previous work on another similar object, 2021 DW1 (Kwiatkowski et al. 2021). The main objective of this project is to use lightcurves observed during one apparition along the long arc in the sky to derive NEA spin axes. They are then used to compute object obliquities to test the end states of the YORP evolution, which according to some theories should be close to 0 or 180 deg.</p><p>After the discovery of 2022 AB on 2 January 2022 it became known that it would be observable from many different viewing/illumination geometries while maintaining a decent magnitude V<19 mag. The absolute magnitude of 2022 AB, H=23.6 (reported by the MPC) suggested that it could be a super-fast rotating asteroid (rotation period P<2.1 hours), with a diameter D<150~m. The small size of this object means that its rotation can be strongly influenced by YORP.</p><p>We observed 2022 AB photometrically from 4 Jan to 26 Jan, from 27 locations around the world, from Australia, through South Korea, Europe, the United States, to Hawaii. The telescope sizes ranged from 0.28-m to 10.0-m. During that time we collected 89 lightcurves exposed through different filters. The analysis of such rich data sets is time consuming and, until now, we only have some partial results. The object has a synodical period of rotation of 182 seconds, and most likely belongs to the Cb taxonomic class (see a poster by Kole&#324;czuk et al. at this conference for details).</p><p>At the conference, we will present full physical characterisation of 2022 AB, including its spin axis, shape, mag-phase curve, taxonomy, and size. We will discuss the obliquity of its rotation axis in the context of YORP evolution.</p><p>Acknowledgements</p><p>PK acknowledges support from the National Science Centre, Poland, Grant No. 2021/41/N/ST9/04259.</p><p>References</p><p>T. Kwiatkowski, P. Kole&#324;czuk, A. Kryszczy&#324;ska, D. Oszkiewicz, K. Kami&#324;ski, M. K. Kami&#324;ska, V. Troianskyi, B. Skiff, N. Moskowitz, V. Kashuba, M.-J. Kim, T. Kim, S. Mottola, T. Santana-Ros, T. Kluwak, L. Buzzi, P. Bacci, P. Birtwhistle, R. Miles, and J. Chatelain (2021), Photometry and model of near-Earth asteroid 2021 DW1 from one apparition, A&A 656, A126</p><p>&#160;</p>