against proper motion in right ascension of the Sgr stream. Top: all stars selected by distance superimposed on the histogram obtained from the mock catalogue (see text). Bottom: result of the TGM (green and red error bars) and the area that we use to further filter out the contamination (orange). Here we also show the prediction of the LM10 model with green lines. The stars at the trailing apocentre have been moved to the left of the plot by subtracting −360°.