  As part of our radial velocity planet-search survey performed with SARG at
TNG, we monitored the components of HD 132563 for ten years. It is a binary
system formed by two rather similar solar type stars with a projected
separation of 4.1 arcsec, which corresponds to 400 AU at the distance of 96 pc.
The two components are moderately metal-poor and the age of the system is about
5 Gyr. We detected RV variations of HD 132563B with period of 1544 days and
semi-amplitude of 26 m/s. From the star characteristics and line profile
measurements, we infer their Keplerian origin. Therefore HD 132563B turns out
to host a planet with a projected mass msini=1.49 MJup at 2.6 AU with a
moderately eccentric orbit (e=0.22). The planet around HD 132563B is one of the
few that are known in triple stellar systems, as we found that the primary HD
132563A is itself a spectroscopic binary with a period longer than 15 years and
an eccentricity higher than 0.65. The spectroscopic component was not detected
in adaptive-optics images taken with AdOpt@TNG, since it expected at a
projected separation that was smaller than 0.2 arcsec at the time of our
observations. A small excess in K band difference between the components with
respect to the difference in V band is compatible with a companion of about
0.55 Msun. A preliminary statistical analysis of the occurrence of planets in
triple systems indicate a similar frequency of planets around the isolated
component in a triple system, components of wide binaries and single stars.
There is no significant iron abundance difference between the components. The
lack of stars in binary systems and open clusters showing strong enhancements
of iron abundance, comparable to the typical metallicity difference between
stars with and without giant planets, agrees with the idea that accretion of
planetary material producing iron abundance anomalies larger than 0.1 dex is
rare.
