Comparison of the solar spectrum (black) to the spectrum of the solar analog KIC 10644253 observed with the HERMES spectrograph. The regions around the Ca K line and the lithium multiplet at 670.78 nm are respectively shown in the left and right panels. The flux ratio (blue) of the two spectra between KIC 10644253 and the Sun (left), and between the Sun and KIC 10644253 (right) are also shown after shifting them by −0.45 and +0.1 respectively.