Polarization and photometric observations of the gamma-ray blazar PG 1553+113

ANDRUCHOW, I.; COMBI, J. A.; MUÑOZ-ARJONILLA, A. J.; ROMERO, G. E.; CELLONE, S. A.; MARTÍ, J.

ASTRONOMY & ASTROPHYSICS. SUPPLEMENT SERIES (PRINT)

EDP Sciences

Año: 2011 vol. 531 p. 38 - 41

0365-0138

We present the results of an observational photo-polarimetry campaign of the blazar PG 1553+113 at optical wavelengths. The blazar was recently detected at very high energies (>100 GeV) by the HESS and MAGIC γ-ray Cherenkov telescopes. Our high-temporal resolution data show significant variations in the linear polarization percentage and position angle at inter-night time-scales, while at shorter (intra-night) time-scales both parameters varied less significantly, if at all. Changes in the polarization angle seem to be common in γ-ray emitting blazars. Simultaneous differential photometry (through the B and R bands) shows no significant variability in the total optical flux. We provide B and R magnitudes, along with a finding chart, for a set of field stars suitable for differential photometry.