The evolutionary state and fundamental parameters of metallic A-F giants

Abstract

Using Hipparcos parallaxes, we show that the metallic A-F giants found by Hauck on the basis of their high Delta m(2) index in Geneva photometry are on average more evolved than their non-metallic counterparts. Their mass distribution, rate of binaries and v sin i are shown to be incompatible with those of Am stars, so that they cannot be descendants of the latter. They might be former normal stars going through a short metal-rich phase at the very end of their life on the Main Sequence.