(3200) Phaethon polarimetry in the negative branch: new evidence for the anhydrous nature of the DESTINY+ target asteroid
Abstract
We report on the first polarimetric study of (3200) Phaethon, the target of JAXA's DESTINY+ mission, in the negative branch to ensure its anhydrous nature and to derive an accurate geometric albedo. We conducted observations at low phase angles (Sun-target-observer angle, α = 8.8-32.4°) from 2021 October to 2022 January and found that Phaethon has a minimum polarization degree Pmin = -1.3 ± 0.1 per cent, a polarimetric slope h = 0.22 ± 0.02 per cent deg-1, and an inversion angle α0 = 19.9 ± 0.3°. The derived geometric albedo is pV = 0.11 (in the range of 0.08-0.13). These polarimetric properties are consistent with anhydrous chondrites, contradict hydrous chondrites, and typical cometary nuclei.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- October 2022
- DOI:
- 10.1093/mnrasl/slac072
- arXiv:
- arXiv:2208.11912
- Bibcode:
- 2022MNRAS.516L..53G
- Keywords:
-
- techniques: polarimetric;
- minor planets;
- asteroids: individual: (3200) Phaethon;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 6 pages, 2 figures, This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society: 2022 Jooyeon Geem, Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. For the published version, please see https://academic.oup.com/mnrasl/article/516/1/L53/6639881