The multimode pulsation of the δ Scuti star V784 Cassiopeae^*

¹ Department of Experimental Physics and Astronomical Observatory, University of Szeged, Szeged, Dóm tér 9., 6720, Hungary
² Guest Observer, Sierra Nevada Observatory, IAA-CSIC
³ Hungarian Eötvös Fellowship, Instituto de Astrofísica de Andalucía, CSIC
⁴ Instituto de Astrofísica de Andalucía, CSIC, PO Box 3004, 18080, Spain
⁵ Baja Astronomical Observatory of Bács-Kiskun County, Baja, PO Box 766, 6501, Hungary
⁶ David Dunlap Observatory, University of Toronto, Richmond Hill, Canada

Corresponding author: L. L. Kiss, l.kiss@physx.u-szeged.hu

Received: 14 November 2001
Accepted: 16 July 2002

Abstract

We present an analysis of new Johnson and Strömgren photometric and medium-resolution spectroscopic observations of the δ Scuti type variable star V784 Cassiopeae. The data were obtained in three consecutive years between 1999 and 2001. The period analysis of the light curve resulted in the detection of four frequencies ranging from 9.15 d^-1 to 15.90 d^-1, while there is a suggestion for more, unresolved frequency components, too. The mean Strömgren indices and Hipparcos parallax were combined to calculate the following physical parameters: 7100 ± 100 K, 3.8 ± 0.1, 150 ± 015. The position of the star in the HR diagram was used to derive evolutionary mass and age yielding to a consistent picture of an evolved δ Scuti star with a mixture of radial plus non-radial modes.