Rotational variation of the linear polarisation of the asteroid (3200) Phaethon as evidence for inhomogeneity in its surface properties

Autor: Yu. N. Krugly, Alberto Cellino, G. Ramsay, Saran Poshyachinda, R. Cutter, V. S. Dhillon, P. T. O'Brien, Kendall Ackley, K. Ulaczyk, Ph. Bendjoya, Martin Dyer, Z. Donchev, Galin Borisov, E. Thrane, D. Vernet, J. P. Rivet, Stefano Bagnulo, Duncan K. Galloway, Don Pollacco, E. Rol, Apostolos A. Christou, Maxime Devogele, L. Abe, Tanyu Bonev, Irina Belskaya, D. Steeghs
Přispěvatelé: ITA, GBR, FRA, BGR, UKR, Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Armagh Observatory [Armagh], Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute of Astronomy, Bulgarian Academy of Sciences (BAS), V.N. Karazin Kharkiv National University (KhNU), National Astronomical Observatory - Rozhen (NAO), Department of Physics and Astronomy [Sheffield], University of Sheffield [Sheffield], University of Minnesota System, Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Astronomical Observatory [Warsaw], Faculty of Physics [Warsaw] (FUW), University of Warsaw (UW)-University of Warsaw (UW)
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Monthly Notices of the Royal Astronomical Society: Letters
Monthly Notices of the Royal Astronomical Society: Letters, Oxford Journals, 2018, 480 (1), pp.L131-L135. ⟨10.1093/mnrasl/sly140⟩
ISSN: 1745-3933
DOI: 10.1093/mnrasl/sly140⟩
Popis: Asteroid (3200) Phaethon is a Near-Earth Apollo asteroid with an unusual orbit that brings it closer to the Sun than any other known asteroid. Its last close approach to the Earth was in mid-December 2017 and the next one will be on October 2026. Previous rotationally time-resolved spectroscopy of Phaethon showed that its spectral slope is slightly bluish, in agreement with its B/F taxonomic classification, but at some rotational phases, it changes to slightly reddish. Motivated by this result we performed time-resolved imaging polarimetry of Phaethon during its recent close approach to the Earth. Phaethon has a spin period of 3.604 hours and we found a variation of the linear polarisation with rotation. This seems to be a rare case in which such variation is unambiguously found, also a consequence of its fairly large amplitude. Combining this new information with the brightness and colour variation, as well as previously reported results from Arecibo radar observations, we conclude that there is no variation of the mineralogy across the surface of Phaeton. However, the observed change in the linear polarisation may be related to differences in the thickness of the surface regolith in different areas or local topographic features.
5 pages, 2 figures, MNRAS Letters
Databáze: OpenAIRE
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