ИСТИНА

Speckle polarimeter (SPP) is a facility instrument of 2.5-m telescope of SAI MSU. By design it is a combination of two-beam polarimeter with rotating half-wave plate (HWP) and EMCCD-based speckle interferometer. The instrument operates in visible range: 0.5-1.1 microns. Simultaneous acquisition of orthogonally polarized radiation and fast modulation by rotating HWP allows to strongly suppress the effects of atmospheric turbulence and obtain a distribution of polarized flux at diffraction limited resolution (0.05 arcsec). As long as the method does not rely on coronagraphic mask the resolving of circumstellar environment as close as 0.05 arcsec to the star is possible. The SPP can be used either in Cassegrain or Nasmyth focus of 2.5-m telescope. For the latter case methods of compensation of instrumental polarization and polarization aberrations were developed. The instrument suits for study of bright and small dusty circumstellar environments of some young stellar objects, mira variables, semiregular variables etc. For V=7 objects SPP reaches contrast of 10^-3 for polarized flux at 0.15” from the central source. Using SPP we resolved the dusty disk wind of enigmatic YSO RW Aur A. Variable circumstellar nebulae were detected for V CVn on angular scales of 0.1-0.15”.