Physical properties of near-Earth asteroid (2102) Tantalus from multi-wavelength observations
Abstract
Between 2010 and 2017 we have collected new optical and radar observations of the potentially hazardous asteroid (2102) Tantalus from the ESO NTT and Danish telescopes at the La Silla Observatory and from the Arecibo planetary radar. The object appears to be nearly spherical, showing a low amplitude light-curve variation and limited large-scale features in the radar images. The spin-state is difficult to constrain with the available data; including a certain light-curve subset significantly changes the spin-state estimates, and the uncertainties on period determination are significant. Constraining any change in rotation rate was not possible, despite decades of observations. The convex lightcurve-inversion model, with rotational pole at λ = 210 ± 41° and β = −30 ± 35°, is more flattened than the two models reconstructed by including radar observations: with prograde (λ = 36 ± 23°, β = 30 ± 15°), and with retrograde rotation mode (λ = 180 ± 24°, β = −30 ± 16°). Using data from WISE we were able to determine that the prograde model produces the best agreement in size determination between radar and thermophysical modelling. Radar measurements indicate possible variation in surface properties, suggesting one side might have lower radar albedo and be rougher at centimetre-to-decimetre scale than the other. However, further observations are needed to confirm this. Thermophysical analysis indicates a surface covered in fine-grained regolith, consistent with radar albedo and polarisation ratio measurements. Finally, geophysical investigation of the spin-stability of Tantalus shows that it could be exceeding its critical spin-rate via cohesive forces.
Citation
Rozek , A , Lowry , S C , Rozitis , B , Dover , L R , Taylor , P A , Virkki , A , Green , S F , Snodgrass , C , Fitzsimmons , A , Campbell-White , J , Sajadian , S , Bozza , V , Burgdorf , M J , Dominik , M , Jaimes , R F , Hinse , T C , Hundertmark , M , Jørgensen , U G , Longa-Peña , P , Rabus , M , Rahvar , S , Skottfelt , J & Southworth , J 2022 , ' Physical properties of near-Earth asteroid (2102) Tantalus from multi-wavelength observations ' , Monthly Notices of the Royal Astronomical Society , vol. 515 , no. 3 , pp. 4551–4564 . https://doi.org/10.1093/mnras/stac1835
Publication
Monthly Notices of the Royal Astronomical Society
Status
Peer reviewed
ISSN
0035-8711Type
Journal article
Rights
Copyright © The Author(s) 2022. Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
Description
Funding: This research has received support from the National Research Foundation (NRF; 2019R1I1A1A01059609), the European Union H2020-SPACE-2018-2020 research and innovation programme under grant agreement No. 870403 (NEOROCKS), the European Union H2020-MSCA-ITN-2019 under grant No. 860470, and the Novo Nordisk Foundation Interdisciplinary Synergy Programme grant no. NNF19OC0057374.Collections
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