SIMBAD references

From a new set of spectroscopic observations we determined orbital parameters of six SB2 systems with one or both components being HgMn stars. We slightly refined the orbital periods for HD32964, HD173524, HD174933 and HD216494. Our results for HD358 are in agreement with the previous literature studies. Regarding HD33647, our orbital period is shorter than previous determinations. HD173524 is a triple system. From the variations of the γ-velocity deduced from our and literature data, we refined the orbital period and we estimated the eccentricity of the third companion, for which we get e ≃0.13 and P_orb=36±3years. HD191110 and HD216494 seem to be the only synchronous SB2 within our sample. Following the hypothesis of rotational axes perpendicular to the orbital plane, we estimated the angle of the orbital plane to the line of sight. We identified in our spectra the signature of the H_β of the third component of HD216494 and we highlight a slight variation of the γ-velocity due to the presence of this component.