Models of Rosetta/OSIRIS 67P dust coma phase function
arXiv:1809.10424 · doi:10.3847/1538-3881/aae526
Abstract
The phase function of the dust coma of comet 67P has been determined from Rosetta/OSIRIS images \citep{Bertini17}. This function show 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 ensamble of oriented elongated particles of a wide variety of aspect ratios, with radii 10 m, 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.
Accepted by Astronomical Journal, September 26th, 2018. 21 pages, 5 figures
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- VIRTIS-H observations of comet 67P's dust coma: spectral properties and color temperature variability with phase and elevation
- HD 117214 debris disk: scattered-light images and constraints on the presence of planets
- Scattering, absorption, and thermal emission by large cometary dust particles: Synoptic numerical solution
- Interpretation through experimental simulations of phase functions revealed by Rosetta in 67P dust coma
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- Dynamics of irregularly-shaped cometary particles subjected to outflowing gas and solar radiative forces and torques
- Observational constraints to the dynamics of dust particles in the coma of comet 67P/Churyumov-Gerasimenko
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