**Table 1:** The barium syndrome among YSyS. The spectral type of the cool component is taken from Mürset & Schmid (1999), or references therein. In column labelled ``nebula'', ``y'' means that an optical nebula has been detected, and ``PN'' that, based on its emission line spectrum, the star has traditionally been included in planetary nebulae catalogues, even though no optical nebula may be visible. The column labelled "P'' lists the orbital period, from Mürset & Schmid (1999).
Name	Sp. typ.	[Fe/H]	V_r	b	[Ba/Fe]	$V \sin \; i$	Nebula	P	Ref.
			(km s^-1)	( $^\circ$ )		(km s^-1)		(d)
d'-type
V417 Cen	G8-K2	$\sim$ 0.0		-1	0.5	70	y	247	(5, 11)
HDE 330036	G5	0.02	-14	+4	0.88	100	PN	-	(14, 17)
=Cn 1-1
AS 201	G5	0.07		+7	0.63	25	y	-	(12, 17)
V471/V741 Per	G5	?	-12	-9	>0		PN	-	(2)
=M 1-2
St H $_\alpha$ 190	G5	0.0	$\sim$ 10	-35	$\sim$ 0.5	100	bip. outf.	-	(10, 13)
Wray 157	G5	?
Hen 1591	<K4	?
s-type
UKS Ce-1	C4, 5Jch	?	+20	+20	>0			-	(6)
S 32	C1, 1CH	?	+325	-30	>0			612	(6, 14)
Hen 2-467	K0	-1.1	-109	-12	+0.8		n	478	(4, 16)
BD $-21^\circ$ 3873	K2	-1.1	+204	+37	+0.5		n	282	(3, 15, 16)
		-1.3			+0.3				(9)
AG Dra	K2	-1.3	-148	+41	+0.5		n	554	(8, 16)
CD $-43^\circ$ 14304	K7	-1.4	+27	-41	?			1448	(7, 18)
Chemical evolution of the Galaxy
		-1.0			<0.2				(1)

References: (1) Edvardsson et al. 1993, A&A, 275, 101; (2) Grauer & Bond 1981, PASP, 93, 630; (3) Pereira et al. 1997, AJ, 114, 2128; (4) Pereira et al. 1998, AJ, 116, 1977; (5) Pereira et al. 2003, in Symbiotic stars probing stellar evolution, ed. R. L. M. Corradi, J. Miko $\l$ ajewska, & T. J. Mahoney, Astron. Soc. Pacific Conf. Ser. (San Francisco), 85; (6) Schmid 1994, A&A, 284, 156; (7) Schmid et al. 1998, A&A, 329, 986; (8) Smith et al. 1996, A&A, 315, 179; (9) Smith et al. 1997, A&A, 324, 97; (10) Smith et al. 2001, ApJ, 556, L55; (11) Van Winckel et al. 1994, A&A, 285, 241; (12) Schwarz 1991, A&A, 243, 469; (13) Munari et al. 2001, A&A, 369, L1; (14) Schmid & Nussbaumer 1993, A&A, 268, 159; (15) Munari & Patat 1993, A&A, 277, 195; (16) Corradi et al. 1999, A&A, 343, 841; (17) Pereira et al. 2005, A&A, 429, 993; (18) The metallicity is from Pereira, priv. comm.

Source LaTeX | All tables | In the text

	1 The problem
	2 The samples
	3 Abundances
	4 Statistics of binarity among metal-deficient Ba stars
	5 Summary of the binary criteria and discussion
	References
	Online Material