Recent progress in CP star detection and classification

Chemically peculiar (CP) stars are mainly found among B and A stars. Present theories are not able to account fully for the observed spectrum anomalies, suggesting that in the atmospheres of stars in the range ofT _e , where mass loss is no longer very large and convection is still not very important, the present theoretical approach needs further refinement. Moreover, the lack of laboratory data is responsible, at least partly, for the discrepancies between observed and computed stellar energy distributions.The choice for quick detection of CP stars among faint objects is reviewed; the measure of the flux depression at 5200 appears to be very powerful, and the identification of this complex feature is urgently needed.The need to separate the various subclasses of the He abnormal stars in a standard way is underlined and further analyses of the characteristics of the Boo stars are required.The problem of the determination ofT _e and consequently of realistic atmospheric abundance anomalies of CP stars is discussed.