Full Table 1 is only available in electronic form at http://www.edpsciences.org

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Based on observations collected with the ADONIS instrument at the European Southern Observatory, La Silla, Chile (65.H-0568(A) and 67.D-0220(A)).

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... East)

The astrometric calibrations are based on observations of the astrometric reference field ( $\theta$ Ori) for ADONIS/SHARPII+/NICMOS3 (see http://www.imcce.fr/priam/adonis). Mean values for the period 9/1999 to 12/2001 are used. Plate scale and position angle differences between the two observing runs fall within the error bars.

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... La Silla

see http://www.ls.eso.org/lasilla/sciops/ntt/sofi

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... $0^\circ \leq \varphi < 45^\circ$

This formula is also valid for $90^\circ \leq \varphi < 135^\circ$ , $180^\circ \leq \varphi < 125^\circ$ , and $270^\circ \leq \varphi < 315^\circ$ . $Q(\varphi)=L^2/8 \sin^2\varphi$ for all other position angles between $0^\circ$ and $360^\circ$ .

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... $F_{\rm C}$

Note that in Kouwenhoven et al. (2004b,a) we used an incorrect definition of $F_{\rm C}$ .

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