Research Note

C, N, O in  Boo stars and in composite spectra

¹ Dipartimento di Astronomia, Università degli Studi di Trieste, via G. B. Tiepolo 11, 34131 Trieste, Italy e-mail: faraggiana@ts.astro.it
² Istituto Nazionale per l'Astrofisica – Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, 34131 Trieste, Italy

Received: 2 October 2004
Accepted: 14 March 2005

Abstract

The selective abundance of C, N, O (almost solar) with respect to that of other elements (underabundant) in λ 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 λ Boo stars.