Dust in Comet 103P/Hartley 2 coma during EPOXI mission

Imaging polarimetry of comet 73P/Schwassmann–Wachmann 3 main fragments during its 2006 apparition

“…comet 103P/Hartley 2 which is a low-P max comet; comparisons with results obtained through ESA cometary continuum narrow band filters (684 nm,  = 9 nm and 443 nm,  = 4 nm) have shown the absence of any major contamination when using the broad Thuan-Gunn filter (Hadamcik et al, 2013;2014).…”

Linear polarization measurements of Comet C/2011 W3 (Lovejoy) from STEREO

“…Hadamcik et al (2013) points out that the degree of polarization in the positive branch decreases with decreasing size of particles for aggregates or compact particles larger than the wavelength, the opposite is true for transparent materials in fluffy aggregates with grain size smaller than 0.2 microns or for submicron-sized compact particles, where the degree of polarization tends to increase with decreasing size, and the maximum polarization can be as high as 80-90%.…”

The Composition of Comets

“…The averaged polarization, measured through different increasing aperture sizes (e.g., Kiselev et al 2001;Hadamcik et al 2013), provides the whole coma polarization when using large apertures (Hadamcik and Levasseur-Regourd 2003b), for a given phase angle and wavelength. Polarimetric phase curves show a small negative branch (down to about −1 to −2 %), and inversion angle near 20 • , and a broad positive branch with a maximum (up to about 15 to 30 %) by 90 • to 100 • (e.g.…”