1. Radial Distribution of the Dust Comae of Comets 45P/Honda-Mrkos-Pajdus̆áková and 46P/Wirtanen
- Author
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C. Lejoly, W. Harris, N. Samarasinha, B. E. A. Mueller, E. Howell, J. Bodnarik, A. Springmann, T. Kareta, B. Sharkey, J. Noonan, L. R. Bedin, J.-G. Bosch, A. Brosio, E. Bryssinck, J.-B. de Vanssay, F.-J. Hambsch, O. Ivanova, V. Krushinsky, Z.-Y. Lin, F. Manzini, A. Maury, N. Moriya, P. Ochner, and V. Oldani
- Subjects
Geophysics ,Space and Planetary Science ,Earth and Planetary Sciences (miscellaneous) ,Astronomy and Astrophysics - Abstract
There was an unprecedented opportunity to study the inner dust coma environments, where the dust and gas are not entirely decoupled, of comets 45P/Honda–Mrkos–Pajdus̆áková (45P/HMP) from 2016 December 26 to 2017 March 15, and 46P/Wirtanen from 2018 November 10 to 2019 February 13, both in visible wavelengths. The radial profile slopes of these comets were measured in the R and HB-BC filters most representative of dust, and deviations from a radially expanding coma were identified as significant. The azimuthally averaged radial profile slope of comet 45P/HMP gradually changes from −1.81 ± 0.20 at 5.24 days preperihelion to −0.35 ± 0.16 at 74.41 days postperihelion. Contrastingly, the radial profile slope of 46P/Wirtanen stays fairly constant over the observed time period at −1.05 ± 0.05. Additionally, we find that the radial profile of 46P/Wirtanen is azimuthally dependent on the sky-plane-projected solar position angle, while that of 45P/HMP is not. These results suggest that comets 45P/HMP and 46P/Wirtanen have vastly different coma dust environments and that their dust expansion properties are distinct. As evident from these two comets, well-resolved inner comae are vital for detailed characterization of dust environments.
- Published
- 2022