Models of Rosetta/OSIRIS 67P Dust Coma Phase Function

DOI: 
10.3847/1538-3881/aae526
Publication date: 
01/11/2018
Main author: 
Moreno, F.
IAA authors: 
Moreno, F.;Guirado, D.;Muñoz, O.;Lara, L. M.;Gutiérrez, P. J.;López-Moreno, J. J.
Authors: 
Moreno, F.;Guirado, D.;Muñoz, O.;Bertini, I.;Tubiana, C.;Güttler, C.;Fulle, M.;Rotundi, A.;Della Corte, V.;Ivanovski, S. L.;Rinaldi, G.;Bockelée-Morvan, D.;Zakharov, V. V.;Agarwal, J.;Mottola, S.;Toth, I.;Frattin, E.;Lara, L. M.;Gutiérrez, P. J.;Lin, Z. Y.;Kolokolova, L.;Sierks, H.;Naletto, G.;Lamy, P. L.;Rodrigo, R.;Koschny, D.;Davidsson, B.;Barucci, M. A.;Bertaux, J. -L.;Bodewits, D.;Cremonese, G.;Da Deppo, V.;Debei, S.;De Cecco, M.;Deller, J.;Fornasier, S.;Ip, W. -H.;Keller, H. U.;Lazzarin, M.;López-Moreno, J. J.;Marzari, F.;Shi, X.
Journal: 
The Astronomical Journal
Refereed: 
Yes
Publication type: 
Article
Volume: 
156
Pages: 
237
Abstract: 
The phase function of the dust coma of comet 67P has been determined from Rosetta/OSIRIS images. This function shows a deep minimum at phase angles near 100°, and a strong backscattering enhancement. These two properties cannot be reproduced by regular models of cometary dust, most of them based on wavelength-sized and randomly oriented aggregate particles. We show, however, that an ensemble of oriented elongated particles of a wide variety of aspect ratios, with radii r ≳ 10 μm, and whose long axes are perpendicular to the direction of the solar radiation, are capable of reproducing the observed phase function. These particles must be absorbing, with an imaginary part of the refractive index of about 0.1 to match the expected geometric albedo, and with porosity in the 60%─70% range.
Database: 
ADS
SCOPUS
URL: 
https://ui.adsabs.harvard.edu/#abs/2018AJ....156..237M/abstract
ADS Bibcode: 
2018AJ....156..237M
Keywords: 
methods: numerical;minor planets;asteroids: individual: 67P&Churyumov─Gerasimenko;Astrophysics - Earth and Planetary Astrophysics