As reported half a year ago, we need more observations of polarized and zero-polarization standards in photometric conditions in order to assess the current polarimetric mode of NOTCam. Unfortunately, the weather has not helped. Some data was obtained in March of one zero-polarization and one high-polarization standard in the J and H filters, but the apparently clear night was probably not quite photometric. The preliminary data reduction gives quite a high polarization for the zero-polarization standard. Thus, commissioning of these polaroids continues.

It is evident that an upgrade to Wollaston prisms would be the way to go for NOTCam polarimetry, but we have not yet looked in to this option.

Thomas Augusteijn 2009-05-14