ИСТИНА

We present the results of polarization observations performed with the MASTER Global Robotic Net for one supernova and two blazars. Photometry in polarizers is presented for Type Ia Supernova 2012bh, starting on March 27. We find that linear polarization of SN 2012bh at the early stage of the envelope expansion was less than 3%. Polarization measurements for blazars OC 457, 3C 454.3 are presented. Blazars OC 457 and 3C 454.3 were observed in polarizers during their periods of activity. We infer the degree of linear polarization and polarization angle. The results show that the MASTER is able to measure substantially polarized light; at the same time it is not suitable for determining weak polarization (less than 5%) of dim objects (fainter than 16m). Polarimetric observations of early optical emission from gamma-ray bursts and supernovae are necessary to get insights into the nature of these transient objects.