taken into account in the proper error propagation. The data from 2006.38 and 2007.13 have the largest errors, which are due to the poor FWHM at these epochs (see Table 1), cc2 is only marginally detected at those two epochs. We therefore exclude those two data points in the parallax determination (Table 3, Figs. 3 and 4), as they do not give any further constraints (they are consistent with the solution given).

[l|cc|cc]{}\
Epoch & &\
year & $\Delta RA$ \[$^{\prime \prime}$\] & $\Delta Dec$ \[$^{\prime \prime}$\] & $\Delta RA$ \[$^{\prime \prime}$\] & $\Delta Dec$ \[$^{\prime \prime}$\]\
2004.48 & $4.3265 \pm 0.0164$ & $4.6473 \pm 0.0175$ & $3.5953 \pm 0.0137$ & $4.5775 \pm 0.0173$\
2005.40 & $4.3120 \pm 0.0164$ & $4.6739 \pm 0.0177$ & $3.5812 \pm 0.0136$ & $4.5969 \pm 0.0174$\
2005.60 & $4.2977 \pm 0.0163$ & $4.6715 \pm 0.0177$ & $3.5703 \pm 0.0135$ & $4.5956 \pm 0.0174$\
2006.14 & $4.3041 \pm 0.0163$ & $4.6909 \pm 0.0178$ & $3.5786 \pm 0.0136$ & $4.6134 \pm 0.0175$\
2006.54 & $4.2888 \pm 0.0163$ & $4.6965 \pm 0.0179$ & $3.5590 \pm 0.0136$ & $4.6272 \pm 0.0179$\

We can first verify that GQ Lup/cc2 is a background star, Figs. 3 and 4, because separation between 