Contribution to the search for binaries among Am stars. III. HD 7119, a double-lined spectroscopic binary and a triple system

International audienceRadial velocity observations of HD 7119 with the CORAVEL instrument at Observatoire de Haute-Provence are reported. Known as an Am/δ Del metallic-line star, HD 7119 was included in our spectroscopic survey of Am-type stars whose purpose was to determine the frequency of binaries in this stellar family. This object is found to be a double-lined spectroscopic binary with a variable value of V 0 , the systematic velocity of the center of gravity of the pair. The variation of this parameter is interpreted in terms of orbital motion of an unseen third body with a much longer period. The orbital elements were derived for both the short and the long period orbits. These orbits can be considered as well determined since these observations were performed on a regular basis over the 1992-1998 period, covering more than 320 orbitalcycles for the short-period (P=6.76 days) and 1.3 cycle for the long-period orbit (P∼1700 days). As deduced from the ratio of the correlation dip areas, the magnitude difference of the components of the short-period system is 0.7 mag. Combined with the Hipparcos data, this value leads to visual absolute magnitudes of 0.5 and 1.2 for the primary and secondary components respectively. Such magnitudes are consistent with evolved δ Del-type stars.The third body could be a cool dwarf star with a minimum mass of 0.5 M ⊙, located at ∼0.016 ′′ of the main system. Consequently, it cannot be the visual companion detected by Couteau with a separation of 3.35 ′′ . If this latter visual component was a physical component, (not an optical one), HD 7119 would be a quadruple syste