We have built a polarimeter called PLANETPOL designed to be capable of measuring the very small polarizations expected from scattered light in an extrasolar planet atmosphere.
PLANETPOL had a very successful observing run on the 4.2m William Herschel Telescope on La Palma during April 2004. During this run we were able to confirm that PLANETPOL met its design goal of measuring stellar polarizations to a sensitivity of one part in a million.
PLANETPOL Instrument Details
Lucas et al., 2008, astroph:0807.2568
Bailey et al., 2008, MNRAS, 386, 1016
Hough et al., 2006, PASP, 118,
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