Core regions of the CaII K (left) and H (right) lines of HD 1237. Four spectra from our sample are plotted with the corresponding dates on the left y-axis and vertically shifted (0.25 units) for visualisation purposes. The black spectrum at the top was taken at a much later epoch (2012 Dec. 07). The red line shows the mean profile for the entire dataset, while the purple line is a HARPS solar spectrum used as reference.