Radial velocity curves of HD 132563

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 0.55M_{sun}_. 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 0.1dex is rare.