SIMBAD references

This paper aims to improve the knowledge of orbits, physical parameters, and statistics of nearby multiple systems. Radial velocities were measured with a correlation spectrometer during 2001-2006 to determine or improve the spectroscopic orbits of the components of some visual multiple systems. We compiled all available observational data and estimated masses and orbital periods in these hierarchical multiple systems. The masses and ages of evolved components are derived by fitting isochrones. We determined three new spectroscopic orbits of close sub-systems (HD 52452B, 157358Aab, 219877B) and improved one more orbit (HD 139461). The composite-spectrum system HD 157358Aab was resolved by speckle-interferometry, and its preliminary combined orbit was computed to guide future interferometric observations. A tentative 21-day orbit for HD 219877A based on published velocities is computed.