Analysis of Coma Dust Optical Properties in Comet C/1995 O1 (Hale–Bopp): II. Effects of Polarization

✍ Scribed by Dana Xavier Kerola; Stephen M. Larson

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 77 KB
• Volume: 149
• Category: Article
• ISSN: 0019-1035
• DOI: 10.1006/icar.2000.6565

✦ Synopsis

Efforts to apply a single-scattering polarized radiative transfer code to interpret photopolarimetric measurements of coma dust optical properties in

Comet Hale-Bopp corroborate previous photometrically derived conclusions concerning the predominance of small sized particles in Hale-Bopp's coma. Calculations of the degree of linear polarization (DP) as a function of observation phase angle (α) produced by prolate spheroidal crystalline olivine particles with effective radii (a = 0.216 µm) are compatible with the comet's measured polarization in standard filters at λ = 0.4845 and 0.684 µm. Our rudimentary "trade-off" studies highlight the extreme sensitivity of DP to dust particle size and shape. A combination of viewing geometry effects in association with enhanced multiple scattering might provide a quantitative explanation of the negative polarization for 0 • ≤ α ≤ 20 • seen in Hale-Bopp and other comets.