Bibcode
Takalo, L. O.; Sillanpaa, A.; Nilsson, K.; Kidger, M.; de Diego, J. A.; Piirola, V.
Bibliographical reference
Astronomy and Astrophysics Supplement Series (ISSN 0365-0138), vol. 94, no. 1, July 1992, p. 37-42.
Advertised on:
7
1992
Citations
68
Refereed citations
65
Description
Results are presented from simultaneous UBVRI photopolarimetric
observations of eight blazars at the 2.56-m Nordic Optical Telescope
during winter 1991. In 3C 66A the highest ever measured polarization,
P(U) = 30.5 percent is observed, with small frequency dependence (FDP),
P being lower toward longer wavelengths. In AO 0235 + 164, large changes
in the polarization level and in the FDP between different nights were
detected. The FDP is seen to be three times more common than the
frequency dependence in the position angle in these blazars.