Based on observations collected at the European Southern Observatory, Chile, proposals number 070.C-0162, 072.C-0593, 074.C-0699, 074.C-0396, 078.C-0386, and 380.C-0179.

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Herbst et al. (2007) give astrometric data derived from the observations in 2002. However, their analysis was carried out independently from ours.

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... ASTROM

See http://www.starlink.rl.ac.uk/star/docs/sun5.htx/sun5.html

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...(Loinard et al. 2007b)

Loinard et al. (2007b) give a distance of 147.6 $\pm$ $0.6~\rm pc$ in the abstract of their paper, but 146.7 $\pm$ $0.6~\rm pc$ in the main text. Only the latter is compatible with the parallax they report.

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... T Tau N

In reality, both N and the center of mass of Sa/b are in orbit around the center of mass of the entire system, but this does not change the formalism if only relative positions are used.

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