The variation of lithium equivalent width in active cool stars.

In an attempt to determine whether the lithium line at 6707 Å comes mainly from the quiet photosphere or from the cooler spots on spotted active stars, the authors have measured line equivalent widths due to Li and also due to Ca I at 6717 Å at various rotation phases on three fast rotating stars, AB Doradus, PZ Telescopium and V1005 Orionis. The results for AB Dor and PZ Tel show there might be some small rotational modulation which can be linked to the best estimate of the spot position from the available photometry. This modulation is less than that expected on the basis of Giampapa's work on sunspot spectra. The Li and Ca I line equivalent widths were found to anticorrelate.