Polarimetry of comets 67P/Churyumov-Gerasimenko, 74P/Smirnova-Chernykh,   and 152P/Helin-Lawrence
  Aims. Polarimetric characteristics of comets at large heliocentric distances is a relatively unexplored area; we extend the idea by adding and analysing the data for three Jupiter family comets (JFCs).   Methods. With the FORS2 instrument of the ESO VLT, we performed quasi-simultaneous photometry and polarimetry of three active JFCs 67P/Churyumov-Gerasimenko, 74P/Smirnova-Chernykh, and 152P/Helin-Lawrence.   Results. We obtained in total 23 polarimetric measurements at different epochs, covering a phase-angle range ~1 -16 degrees and heliocentric distances from 3 to 4.6 au. From our observations we obtained both colour and polarimetric maps to look for structures in the comae and tails of the comets.   Conclusions. 74P/Smirnova-Chernykh and 152P/Helin-Lawrence exhibit enough activity at large heliocentric distances to be detectable in polarimetric measurements. Polarimetric and colour maps indicate no evidence of dust particle 
A. Stinson, S. Bagnulo, G.P. Tozzi, H. Boehnhardt, S. Protopapa, L.   Kolokolova, K. Muinonen, G.H. Jones
astro-ph.EP