Polarimetry

The `Wedged Double Wollaston' (WeDoWo) prism for one-shot polarimetric observations with ALFOSC on loan from Asiago Observatory, Padova, Italy was received and has been installed. Some first checks were made but unfortunately the weather has not been good enough during technical nights to check it in detail, though the performance is not expected to be very different from that in AFOSC on the 1.82m Telescope at Asiago.

The WeDoWo is mounted in the grism wheel and together with the 10 arcsec horizontal slit which is used as mask, it is permanently available in Nordic observing time. The use and performance of the WeDoWo with ALFOSC will be documented and provide on the ALFOSC web-pages for use by observers and proposal applicants.

For circular polarimetry with FAPOL a quick look tool was developed. The script is interactive, where the user marks the target in one image and the script calculates the degree of circular polarisation. Also a more detailed analysis is being made of polarisation standard star observations made with FAPOL, including observations of candidate standard stars currently investigated with Turpol in order to define the relative calibration between these two instruments.

Thomas Augusteijn 2010-05-27