This is an announcement for the paper "On a characterization of separable dual Banach spaces through determinant subspaces of attaining-norm linear forms" by Stefano Rossi. Abstract: Necessary and sufficient conditions for a separable Banach space to be(isometrically isomorphic to) a dual space will be given. Archive classification: math.FA Remarks: 7 pages The source file(s), articolodef.tex: 24589 bytes, is(are) stored in gzipped form as 0909.4980.gz with size 8kb. The corresponding postcript file has gzipped size 66kb. Submitted from: s-rossi@mat.uniroma1.it The paper may be downloaded from the archive by web browser from URL http://front.math.ucdavis.edu/0909.4980 or http://arXiv.org/abs/0909.4980 or by email in unzipped form by transmitting an empty message with subject line uget 0909.4980 or in gzipped form by using subject line get 0909.4980 to: math@arXiv.org.