Two New Multichannel Astronomical Polarimeters

Optical and near infrared spectropolarimetry and imaging polarimetry has recently received considerable attention. A major contributing factor to this renewed interest has been the successful coupling of polarimeters to multi-element detector arrays enabling many spectral and spatial elements to be observed simultaneously. The latest techniques are briefly reviewed and two new polarimeter systems, developed at the Royal Observatory Edinburgh, are described in detail. One system employs a charge coupled device (CCD) and the other uses an image photon counting (Boksenberg) detector. The latter instrument is now in common use at the Anglo-Australian Telescope. Both instruments are computer-controlled and provide on-line data analysis and display. Their performance is illus-trated with recent astronomical data.