Comet 17P Holmes Stokes Parameter Polarization Difference Image from Stinger 450 Classical Cassegrain and FLI CM10 with Polarizing filters


27 x 3 seconds for each of four analyzer orientations: 0, 45, 90, 135 degrees

135-45 = red, 90-0 = green, 135 - 0 = blue

Image taken 2007 1025 0500 UT   (0500z on 25 Oct 2007 UTC)

90 - 0 degrees

135 - 45 degrees

135 - 0 degrees

Comparision to Quanshi Ye's  Processed Optical Image (morphing comparison)

morphing animation

Clear filter (324 seconds)


Read how to make Polarization Difference (Stokes Parameter) Images:

Refereed Journal Abstract:

Polarization of Light Scattered by Cometary Dust Particles: Observations and Tentative Interpretations
Journal Space Science Reviews
Publisher Springer Netherlands
ISSN 0038-6308 (Print) 1572-9672 (Online)
Issue Volume 90, Numbers 1-2 / October, 1999
DOI 10.1023/A:1005250131509
Pages 163-168
Subject Collection Physics and Astronomy
SpringerLink Date Monday, October 25, 2004

A.-Chantal Levasseur-Regourd

Abstract  Analysis of the polarization of light scattered by cometary particles reveals similarities amongst the phase curves, together with some clear differences: i) comets with a strong silicate emission feature present a high maximum in polarization, ii) the polarization is always slightly lower than the average in inner comae and stronger in jet-like structures. These results are in excellent agreement with the Greenberg model of dust particles built up of fluffy aggregates of much smaller grains. Also, they suggest the existence of different regions of formation, and of different stages of evolution for the scattering particles inside a given cometary coma.
Comets - Dust particles - Scattering - Polarization


Taken on October 24, 2007 from my backyard in Castro Valley, California

Stinger 450 Classical Cassegrain (18" f/12.6)  

Lumicon Giant Easy Guider with Focal reducer for final: F= 3366mm, f/7.1

(image scale = 0.42 arc-sec/pixel at capture)

Finger Lakes CM10 MaxCam imaging camera operated at -25C


Finger Lakes CFW1 Filter wheel

SBIG ST7E guide camera

Analyzing filters

27 exposures of 3 seconds through each analyzer orientation: 0, 45, 90, 135 degrees

324 seconds  total exposure time

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