Radial-velocity orbits of HR 5553 and HR 6524

Determinations are made of the orbital elements for the two single-line spectroscopic binaries HR 5553 and HR 6524. The former is found to have a period of 125.369 days and an eccentricity of 0.51 and the latter a period of 416.1 days and an eccentricity of 0.21. Since there is no evidence of a second star dip in the radial-velocity scans, it is assumed that the second star is fainter in each case. This is seen as implying an upper limit for the mass of the second star which in turn implies a lower limit for the inclination angle (i) for these systems. It is considered extremely unlikely that either of these binaries would produce observable eclipses for any reasonable assumed values of the radii of the secondary stars.