If it is on the main sequence, it has a distance of 800 to 1700 pc, i.e., a parallax of $1.0 \pm 0.3$ mas (even smaller if a giant). Its own proper motion is negligible, as seen above.

The timing of our NACO observations in Feb, May, and Aug 2005 to 2007 was chosen, because the offset in the separation due to parallactic motion is maximal at these times.

The wobble remaining in the motion of GQ Lup A (and its companion) after subtracting the proper motion is then the parallactic motion. In Figs. 3 and 4, we show the data points (difference in position between GQ Lup A and companion, respectively, and the third star cc2), and our best fit giving the parallax of GQ Lup A to be $7.4 \pm 1.9$ mas and the parallax of the GQ Lup companion to be $8.2 \pm 2.1$ mas (full error propagation). For the fit to the GQ Lup A data, the wobbled curve with a non-zero parallax has a reduced $\chi^{2} = 0.036$ for RA and $\chi^{2} = 0.011$ for Dec, while a linear fit (decreasing separation, no parallax) has $\chi^{2} = 0.167$ for RA and 0.037 for Dec. Hence, 