14 Lacertae: A case of shell–orbit coupling?^*

¹ Osservatorio Astronomico di Brera, Via Bianchi 46, I-22055 Merate LC, Italy
² Observatorio Astronómico P. Buenaventura Suarez, C.C. 1129, Asunción, Paraguay
³ Observatoire de la Côte d'Azur, BP. 139, F-06003 Nice Cedex, France
⁴ Observatorio Astronómico Nacional, UNAM, Apdo. 877, Ensenada, B.C. 22800 Mexico

Send offprint request to: M. Bossi

Received: 6 November 1996
Accepted: 5 June 1997

Abstract

We present new photometric and spectroscopic observations of this peculiar Be star: respectively 516 values in 16 nights and 50 spectrograms in 4 nights in the Hα region. A feature of the HeI line profile seems to indicate the presence of a double–lined binary spectrum. Nevertheless, an analysis of our and other available data (former published and unpublished photometry) leads us to rule out the current interpretations of the double–wave light curve shown by this star: 14 Lac can neither be identified as an ellipsoidal variable nor as an eclipsing binary. Its variability is likely to be produced in the circumstellar region by a shell distortion due to the presence of the companion star, even if there is not enough evidence to exclude other hypotheses. The implications both of the duplicity assumption and of its possible refutation are discussed.