Table 4:

Radio to optical polarization characteristics of objects with detected optical circular polarization.

1256-229 (PKS) z =0.481
Date	(Ghz)	(%)	( )	(%)
03/2002		22.32 0.15	157 1d	-
04/2007		15.42 0.16	163 1j	0.18 0.04j
2155-152 (PKS) z=0.672
Date	(Ghz)	(%)	( )	(%)
08/1984		32.70 1.30	6 1a	-
04/2007		17.67 0.49	51 1j	-0.35 0.10j
09/2007	85.6	11.04 0.53	52 1i	<0.93i
03/2003	15.4	3.66	-f	<0.34f
1979-1999	8.0	4.81 (mean)	-h	-
		15.3 (max)	-h	-
0219+428 (3C66A) z =0.444
Date	(Ghz)	(%)	( )	(%)
01/1992	[w]	31.07 0.31	39 1b	0.76 0.10b
12/1999	[w]	26.11 0.19	3 1c	0.16 0.05c
11/2008	85.6	4.36 0.54	3 4i	<0.73i
12/1996	5.0	2.9	-e	<0.20e
1974-1999	8.0	2.96 (mean)	-g	-

Notes. Multi-color measurements in references (b) and (c) were averaged; upper limits are given at 3. References for linear or circular polarization: ^(a) Brindle et al. (1986); ^(b) Takalo & Sillanpää (1993); ^(c) Tommasi et al. (2001b); ^(d) Sluse et al. (2005); ^(e) Homan et al. (2001); ^(f) Homan & Lister (2006); ^(g) Fan et al. (2006); ^(h) Fan et al. (2008); ⁽ⁱ⁾ Agudo et al. (2010); ^(j) this work.