On the relation between supersoft X-ray sources and VY Scl stars: The cases of V504 Cen and VY Scl

Abstract

We summarize our optical monitoring program of VY Scl stars with the SMARTS telescopes, and triggered X-ray as well as optical observations after/during state transitions of V504 Cen and VY Scl.Comment: 4 pages, Proc. of workshop "SuperSoft X-ray Sources - New Developments", ESTEC/Villafranca, May 2009, to appear in A