A high-sensitivity polarimeter using a ferro-electric liquid crystal modulator
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Author
Bailey, J.
Kedziora-Chudczer, Lucyna
Cotton, Daniel V.
Bott, Kimberly
Hough, J.H.
Lucas, P.W.
Attention
2299/16753
Abstract
We describe the HIgh Precision Polarimetric Instrument (HIPPI), a polarimeter built at UNSW (The University of New South Wales) Australia and used on the Anglo-Australian Telescope (AAT). HIPPI is an aperture polarimeter using a ferro-electric liquid crystal modulator. HIPPI measures the linear polarization of starlight with a sensitivity in fractional polarization of ∼4 × 10−6 on low-polarization objects and a precision of better than 0.01 per cent on highly polarized stars. The detectors have a high dynamic range allowing observations of the brightest stars in the sky as well as much fainter objects. The telescope polarization of the AAT is found to be 48 ± 5 × 10−6 in the g′ band