Analysis of stellar activity of F, G and K stars with IUE

Abstract

In this work, we correct in colour (B-V) the calibration between the Mount Wilson (S_MW) and the Mg II index (X_hk) we have presented in previous works. With this calibration, we build a catalog of the Mg II and Ca II indexes for all the F, G and K main sequence stars with high resolution IUE spectra (i.e. 1640 observations of 269 stars). Finally, using the S_MW from this catalog, which correspond to the period between 1978 to 1995, and with the indexes S_MW derived either from CTIO (1992 and 1993) or from CASLEO (2000-2004) spectra, we analyze the magnetic activity of several stars along decades.