urn:nasa:pds:context:instrument:partizanskoye.1m25_azt11.crao5c 1.0 1.10.0.0 Product_Context 2020-02-18 1.0 Initial export from OLAF urn:nasa:pds:context:telescope:partizanskoye.1m25_azt11 instrument_to_telescope Korhonen, T., V. Piirola, and A. Reiz, Polarization measurements at La Silla, ESO Messenger, Dec. 1984, p, 20-24. Shakhovskoy, N.M., The methods for analysis of polarization observation, Izv. Krimskoy Astrophis. Obs. 91, 106-123, 1994. Scaltriti, F., V. Piirola, A. Cellino, E. Anderlucci, L. Corcione, G. Massone, F. Racioppi, and F. Porcu, The UBVRI photopolarimeter of the Torino Astronomical Observatory, Mem. Soc. Astron. It. 60, 243-246, 1989. Piirola, V., Simultaneous five-color (UBVRI) photopolarimeter, in Coyne, G.V., A.M. Magalhaes, A.F.J. Moffat, R.E. Schulte-Ladbeck, S. Tapia, and D.T. Wickramasinghe (eds.), Polarized Radiation of Circumstellar Origin, Univ. of Arizona Press, Tucson, pp. 735-746, 1989. CrAO Five-Channel Photopolarimeter Polarimeter The Crimean Astrophysical Observatory (CrAO) Five-Channel Photopolarimeter is capable of simultaneous polarimetric measurements in UBVRI colors, with four dichroic filters splitting the optical paths of the UBVRI components of white light in such a way as to feed five separate photomultipliers that measure each color simultaneously. A half-wave plate in front of a calcite block splits the incoming radiation into two components with polarization planes mutually orthogonal to each other. Rotation of the half-wave plate by steps of 45 degrees and corresponding measurements of the intensities of the two rays allow the observer to derive the values of the Stokes parameters and hence the value of the degree of linear polarization and the position angle. The construction of the polarimeter allows a direct elimination of the sky background polarization. For more information, see: Piirola, V., Simultaneous five-color (UBVRI) photopolarimeter, in Coyne, G.V., A.M. Magalhaes, A.F.J. Moffat, R.E. Schulte-Ladbeck, S. Tapia, and D.T. Wickramasinghe (eds.), Polarized Radiation of Circumstellar Origin, Univ. of Arizona Press, Tucson, pp. 735-746, 1989. This book may be difficult to obtain, so a more accessible publication with information about the instrument is: Scaltriti, F., V. Piirola, A. Cellino, E. Anderlucci, L. Corcione, G. Massone, F. Racioppi, and F. Porcu, The UBVRI photopolarimeter of the Torino Astronomical Observatory, Mem. Soc. Astron. It. 60, 243-246, 1989. See also: Korhonen, T., V. Piirola, and A. Reiz, Polarization measurements at La Silla, ESO Messenger, Dec. 1984, p, 20-24. For methods of observation and data processing, see: Shakhovskoy, N.M. 1994. The methods for analysis of polarization observation. Izvestiya Krimskoy Astrophisicheskoy Observatorii 91, 106-123. (In Russian).