Upper panel: three representative spectra of SDSS J0929+0238 in the range of Ca ii-K (vertical dotted line) obtained on different dates and smoothed by 10 km s^-1. The presence of several stars contributing to the spectra is evident from the clear asymmetry of Ca ii-K (highlighted by the vertical dashed lines) in the spectra corresponding to the multiple peak in the CCF. Lower panel: the corresponding cross-correlation functions.