3 Spectroscopic orbits and system parameters

The final orbital elements were found by least-squares fitting with weights inversely proportional to the square of formal velocity errors. The elements and their formal errors are given in Table 3. For circular orbits I checked that non-zero eccentricity did not result in the significant improvement of the quality of fit, and give in Table 3 the upper limits of eccentricity (95% confidence) as defined by Lucy & Sweeny (1971). Number of measurements used (primary and secondary lines counted separately) and the rms error of unit weight are given in the 9th column of Table 3. Its last column contains mass function for single-lined systems or $M{\rm sin}^3i$ for the components of double-lined systems. Radial velocity curves are given in Fig. 1. Individual observations, their errors and residuals can be found in Table 4 which is available in electronic form only. It contains also the measurements of non-variable components (a total of 382 velocities of 20 components). The 7 CORAVEL measurements are marked as COR in the last column. The 12 measurements rejected in orbit computations are marked by colons.

For the components with apparently constant velocities, the detection threshold on amplitude is from 0.5 to 2 km s^-1 (50% chance of detection). The detection model developed in Tokovinin (1992) indicates that the threshold is about $5\sigma$, where $\sigma$ is the error of the mean velocity as given in Table 2.

  

Figure 1: Radial velocity curves. Radial velocities of primary components are plotted as filled circles and full lines, those of secondary components as empty circles and dashed lines. For ADS 497A the data of Latham et al. (1988) are plotted as triangles. Error bars are shown only for orbits with low amplitudes

  

Table 3: Orbital elements

Magnitude difference of the components of double-lined systems was determined by fitting simultaneously the ratio of dip equivalent widths EW and the combined B-V color, as in Paper I.

The models of multiple systems are given in Table 5. The first column contains ADS numbers, parallaxes and distance moduli. The second column gives component identification (visual components are marked by upper-case letters, spectroscopic components by second lower-case letters). Then in Cols. 3 to 6 the estimated visual magnitudes, spectral types, and masses of components are given. These estimates come from the magnitude differences of double-lined systems and from spectral type assignments that would match absolute magnitude, observed colors and equivalent widths. Thus the data in the left half of Table 5 represent an "educated guess'' based on the available observational data, not the directly measured quantities. Lower limits of secondary mass are given for single-lined systems.

Each hierarchical multiple system can be decomposed into a number of binary systems. The last four columns of Table 5 summarize the parameters of these "elementary'' binaries. Column "type'' has obvious coding: CPM for common proper motion pairs, VB for visual binaries, SB1 and SB2 for single- and double-lined spectroscopic binaries. The periods of CPM pairs are estimated by the third Kepler law from separation and total mass.