A detailed view of the Fundamental Plane of early-type galaxies in clusters at z∼0.2

We present a spectroscopic sample of 48 early-type galaxies in the rich cluster Abell 2218 and 50 galaxies in Abell 2390. Since both samples are very similar, we combine them and investigate a total number of 98 early-type galaxies at z ∼ 0.2. A subsample of 34 galaxies with HST structural properties is used to construct the Fundamental Plane. Elliptical and S0 galaxies show a zeropoint offset of overline{m}_r∼0.43 mag with respect to the local Coma FP. Both sub-samples, ellipticals and lenticulars, exhibit a similar, mild evolution and small scatter. The moderate amount of luminosity evolution is consistent with stellar population models of passive evolution, if z_f≥2 is assumed.