There was an unprecedented opportunity to study the inner dust coma
environment, where the dust and gas are not entirely decoupled, of comets
45P/Honda-Mrkos-Pajdu\u{s}\'akov\'a (45P/HMP) from Dec. ...26, 2016 - Mar. 15,
2017, and 46P/Wirtanen from Nov. 10, 2018 - Feb. 13, 2019, 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 $\pm$ 0.20 at 5.24
days pre-perihelion to -0.35 $\pm$ 0.16 at 74.41 days post perihelion.
Contrastingly, the radial profile slope of 46P/Wirtanen stays fairly constant
over the observed time period at -1.05 $\pm$ 0.05. Additionally, we find that
the radial profile of 46P/Wirtanen is azimuthally dependent on the
skyplane-projected solar position angle, while that of 45P/HMP is not. These
results suggest that comet 45P/HMP and 46P/Wirtanen have vastly different coma
dust environments and that their dust properties are distinct. As evident from
these two comets, well-resolved inner comae are vital for detailed
characterization of dust environments.
There was an unprecedented opportunity to study the inner dust coma environment, where the dust and gas are not entirely decoupled, of comets 45P/Honda-Mrkos-Pajdu\u{s}áková (45P/HMP) from Dec. 26, ...2016 - Mar. 15, 2017, and 46P/Wirtanen from Nov. 10, 2018 - Feb. 13, 2019, 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 \(\pm\) 0.20 at 5.24 days pre-perihelion to -0.35 \(\pm\) 0.16 at 74.41 days post perihelion. Contrastingly, the radial profile slope of 46P/Wirtanen stays fairly constant over the observed time period at -1.05 \(\pm\) 0.05. Additionally, we find that the radial profile of 46P/Wirtanen is azimuthally dependent on the skyplane-projected solar position angle, while that of 45P/HMP is not. These results suggest that comet 45P/HMP and 46P/Wirtanen have vastly different coma dust environments and that their dust properties are distinct. As evident from these two comets, well-resolved inner comae are vital for detailed characterization of dust environments.