The HPOL Spectropolarimeter at Ritter Observatory

Abstract

The HPOL spectropolarimeter, previously operated by the University of Wisconsin at Pine Bluff Observatory (PBO), has been restored and relocated to the University of Toledo's Ritter Observatory. We achieved first light with HPOL at Ritter Observatory on 2012 March 11. We present a detailed instrument description of HPOL in its current configuration at Ritter Observatory, and a description of the standard observing procedure. We performed frequent observations of unpolarized standard stars to calibrate the instrumental polarization. We present polarimetric calibration results for observations spanning 2012 March 11 to 2013 May 2. Our calibration work shows that the systematic uncertainties of observations obtained with HPOL at Ritter Observatory are comparable to, and sometimes outperform, the systematic uncertainties obtained at PBO. We have successfully recommissioned the HPOL spectropolarimeter at Ritter Observatory, making it once again available for ongoing science observations.