Based on observations collected at the European Southern Observatory, Chile, using FEROS spectrograph (proposal ID: 69.D-0338-70.D-0081).

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

Tables 2-4 are only available in electronic form at http://www.edpsciences.org

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

... tham 1.0 mag

Three pairs with larger magnitude difference, namely HIP 70264, HIP 76446, and HIP 78024, were also observed and included in this paper.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

... IRAF

IRAF is distributed by the National Optical Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under contract with the National Science Foundation.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

...)

B-V is available for most of the program stars from Tycho. Tycho photometry has been calibrated into the standard system as in Bessell (2000).

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

... color

In the case of HIP 78416A, the chromospheric emission is clearly shifted in velocity with respect to the center of the absorption line. It appears that the component Ab is more active than Aa. The S index measurement in Table 4 is the one measured for the RV of Aa.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.