C,N,O in lambda Boo stars and in composite spectra
  The selective abundance of C, N, O (almost solar) with respect to that of other elements (underabundant) in lambda Boo stars has been interpreted as a characteristic peculiarity of these objects, when considered as single stars. We show here that a similar selective abundance is predicted from the composite spectra resulting from two unresolved stars in the same temperature range as the lambda Boo stars. 
R. Faraggiana (1) and P. Bonifacio (2) ((1) Dipartimento di   Astronomia, Universita' degli Studi di Trieste, (2) Istituto N...