The rapidly rotating δ Scuti star AV Cetei^*

¹ European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Santiago 19, Chile
² Institut für Astronomie, Universität Wien, Türkenschanzstrasse 17, 1180 Vienna, Austria
³ South African Astronomical Observatory, PO Box 9, Observatory 7935, South Africa
⁴ Department of Physics, University of the North-West, Private Bag X2046, Mmabatho 2735, South Africa
⁵ Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark

Corresponding author: T. H. Dall, tdall@eso.org

Received: 18 June 2003
Accepted: 22 August 2003

Abstract

We present results from an international spectroscopic and photometric campaign on the δ Scuti star AV Cet. The star has a rich and complex pulsation spectrum, and we find 7 individual frequencies, with evidence for many more present below our detection limit. We investigate the prospects for mode identification in fast rotators, using several different techniques. We compare the methods and conclude that although no single technique can give unambiguous mode identification, the collective evidence does allow some conclusions to be drawn, suggesting the presence of one radial mode at 14.598 d^-1. During the campaign we found the star HD 9139 to be a variable. From our photometry we find evidence for a variability time scale around 1 day, but we cannot find an unambiguous interpretation for its light variations.