Table 1: Relative astrometry and photometry for $\varepsilon $ Indi Ba and $\varepsilon $ Indi Bb. The image scale in the NACO S27 camera was measuredas $27.07\pm 0.05$ mas/pixel during NACO commissioning using astrometric binaries and Galactic Centre imaging. The system positionangle offset was measured using images taken of the astrometric binary WDS 19043-2132 on August 13 in the same camera configuration: the error in the determination was $\pm $0.143$^{\circ }$. The separation and position angle were confirmed in independent data taken in another NACO mode, for which the image scale was measured using both WDS 19043-2132 and a non-astronomical opto-mechanical setup. The errors in the mean separation and position angle include the NACO data measurement errors and the errors in the system parameters. Differential magnitudes measured by Volk et al. (2003) and Smith et al. (2003) at other wavelengths are also given for convenience.
Separation (arcsec)
J 0.733
H 0.732
$K_{\rm s}$ 0.731
mean $0.732\pm 0.002$
Position angle ($^{\circ }$ E of N)
J 136.81
H 136.78
$K_{\rm s}$ 136.83
mean $136.81\pm 0.14$
$\Delta$ mag (Bb - Ba) (NACO)
J $0\hbox{$.\!\!^{\rm m}$ }94\pm0\hbox{$.\!\!^{\rm m}$ }02$
H $1\hbox{$.\!\!^{\rm m}$ }76\pm0\hbox{$.\!\!^{\rm m}$ }02$
$K_{\rm s}$ $2\hbox{$.\!\!^{\rm m}$ }18\pm0\hbox{$.\!\!^{\rm m}$ }03$
$\Delta$ mag (Volk et al. 2003)
I $1\hbox{$.\!\!^{\rm m}$ }5$
1.083  ${\mu }$m $0\hbox{$.\!\!^{\rm m}$ }69$
1.282  ${\mu }$m $0\hbox{$.\!\!^{\rm m}$ }47$
1.556  ${\mu }$m $1\hbox{$.\!\!^{\rm m}$ }34$
2.106  ${\mu }$m $1\hbox{$.\!\!^{\rm m}$ }92$
2.321  ${\mu }$m > $3\hbox{$.\!\!^{\rm m}$ }8$
$\Delta$ mag (Smith et al. 2003)
1.647  ${\mu }$m $1\hbox{$.\!\!^{\rm m}$ }9$
2.321  ${\mu }$m > $\mbox{\rm 3}^{\mbox{\rm\tiny m}}$


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