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Appendix A: Notes on individual systems

A.1. Systems unresolved in our study

HD 116114: This star was marked by Renson & Manfroid (2009) as a potential binary with a period of 4000 d. Dommanget & Nys (2002) mark this star in the CCDM catalog as an astrometric binary from Hipparcos.

HD 40711: This star was marked by Renson & Manfroid (2009) as a potential binary with a period of 1245 d.

HD 59435: This star was marked by Renson & Manfroid (2009) as a potential binary with a period of 1386 d.

HD 6532, HD 19918, HD 24712, HD 42659, HD 119027, HD 122970, HD 134214, HD 137949, HD 166473, HD 176232, HD 190290, HD 213637, HD 217522, and HD 218495: There are no references in the literature that indicate multiplicity for these objects.

A.2. Systems resolved in our study, but very likely chance projections

HD 86181: There are no references in the literature that indicate multiplicity for this object. We find a total of eleven objects between K magnitudes 15 and 19, with separations of 3′′ to 8′′ around this star. All of them have chance projection probabilities above 10%.

HD 101065: There are no references in the literature that indicate multiplicity for this object. We detect a new companion candidate to this star at a separation of 8648 and a position angle of 140.9°. A chance projection probability above 5% suggests that this companion candidate might not be a physical companion.

HD 150562: There are no references in the literature that indicate multiplicity for this object. We find a total of 17 objects between K magnitudes 14.5 and 19.5, with separations of 11 to 8′′ around this star. All of them have chance projection probabilities above 3%.

HD 161459: There are no references in the literature that indicate multiplicity for this object. We find two objects with K magnitudes around 18, with separations of 8′′ and 9′′ around this star. Both have chance projection probabilities above 40%.

HD 185256: There are no references in the literature that indicate multiplicity for this object. We detect a new companion candidate to this star at a separation of 4965 and a position angle of 306.7°. A chance projection probability above 6% suggests that this companion candidate might not be a physical companion.

HD 193756: There are no references in the literature that indicate multiplicity for this object. We find two objects with K magnitudes around 16 and 17, with separations of 9′′ and 6′′ around this star. They have chance projection probabilities of 8% and 3%.

HD 196470: There are no references in the literature that indicate multiplicity for this object. We detect a new companion candidate to this star at a separation of 6921 and a position angle of 190.9°. A chance projection probability above 6% suggests that this companion candidate might not be a physical companion.

A.3. Systems resolved in our study

HD 9289: There are no references in the literature that indicate multiplicity for this object. We detect a new companion candidate to this star at a separation of 0441 and a position angle of 72.7°.

HD 12932: There are no references in the literature that indicate multiplicity for this object. We detect a new companion candidate to this star at a separation of 0239 and a position angle of 171.4°.

HD 99563: The Washington Double Star Catalog (Mason et al. 2001) lists a companion at a separation of 18 and a position angle of 218°. Dommanget & Nys (2002) list this component in the CCDM catalog at a separation of 17 and a position angle of 213°. We find this companion at a separation of 1784 and a position angle of 216.6°.

HD 201601: The Washington Double Star Catalog (Mason et al. 2001) lists one companion at a distance between 15 and 21 and position angles between 264° and 277°, a second companion at a distance between 250 and 573, and a third companion at a distance of about 6′. We find the close companion at a distance of 0829 and a position angle of 256.8°. Stelzer et al. (2011) used this new measurement and combined it with the data from the Washington Double Star Catalog and from Hipparcos to derive a preliminary orbit for γ Equ with a period of 274.5 yr. They estimated the mass of the companion to be 0.6  ±  0.4 M_⊙.

HD 203932: There are no references in the literature that indicate multiplicity for this object. We detect a new companion candidate to this star at a separation of 0227 and a position angle of 98.2°.

HD 154708: There are no references in the literature that indicate multiplicity for this object. We find five objects around this star. Only the component AC, with a separation of 0782 at position angle 53.0° and a K magnitude of 12.75 has a chance projection probability below 10^-3. The other four objects between K magnitudes 12.5 and 17.5, with separations of 5′′to 9′′ have chance projection probabilities above 3%.

HD 55719: This system is an SB1 with a period of 46.3140 d, according to the 9th Catalog of Spectroscopic Binary Orbits (Pourbaix et al. 2004). The Washington Double Star Catalog (Mason et al. 2001) lists a companion at a distance of 08 and a position angle of 258°. We find the companion at a separation of 0714 and a position angle of 265.0°.

© ESO, 2012