CONTRIBUTION TO THE STUDY OF COMPOSITE SP ECTRA .6. HD-66068-9

HD 66068-9 is listed by Hynek (1938) as a star having a composite spec trum. Classifications made by various authors and by us indicate that this star is, in fact, an Am one. Our radial velocity observations, ca rried out at the Observatoire de Haute-Provence with the spectroveloci meter CORAVEL, show HD 66068-9 to be a double-lined spectroscopic bina ry with the following orbital elements: P = 7.74799 days; T = 2447600. 690 JD; omega = 341.-degrees-1; e = 0.418; K1 = 56.1 km/s; K2 = 75.1 k m/s; V0 = -21.1 km/s; a1 sin i = 5.43 x 10(6) km; a2 sin i = 7.27 x 10 (6) km; M1 sin3 i = 0.78 M.; M2 sin3 i = 0.58 M.. The system appears t o be a detached one (a congruent-to 25 R.) without possibility of ecli pses (i congruent-to 47-degrees); the secondary component should be an early F dwarf star. The ratio of the corelation dip areas indicates a blue magnitude difference DELTAm approximately 1.6 mag., and the dip area of the primary alone a metallicity [Fe/H] congruent-to 0.37 dex f or the Am star. Rotation-revolution synchronism is discussed: we concl ude that this binary does not rotate synchronically but perhaps that p seudo-synchronization occurs near the periastron passage, according to Hut's theory. Perturbations of some radial velocities during 1983 sug gest the existence of a long period third body.