¹ Astronomical Institute, Academy of Sciences, CZ-25165 Ondrejov, Czech Republic
² European Southern Observatory, Karl-Schwarzschild-Str. 2, D-8574 Garching bei München, Germany
³ Landessternwarte Königstuhl, D-69117 Heidelberg, Germany

Identical line-profile variabilities in HR 4074 and 28 CMa imply a uniform physical mechanism in both stars. The long-term absence of line emission in HR 4074 rules out all circumstellar models.

to be published in ASP Conf. Ser.: IAU Coll. 185: Radial and Nonradial Pulsations as Probes of Stellar Physics, Editors: Conny Aerts, Tim Bedding, Joergen Christensen-Dalsgaard

Preprints from triviniu@eso.org
or on the web at http://www.eso.org/~triviniu/Leuven.html