Instituto de Astrofísica de Andalucía, CSIC, PO Box 3004, 18080 Granada, Spain
2 Instituto de Astronomía, UNAM, PO Box 70-264, 4510 Mexico DF, Mexico
3 Observatoire de la Côte d'Azur, BP 4229, 0634 Nice Cedex 4, France
Corresponding author: E. Rodríguez, email@example.com
Accepted: 12 June 2003
We present the results of simultaneous photometry carried out from 1999 to 2001 of the variable V2109 Cyg together with a spectroscopic analysis based on one high resolution spectrum obtained in 2000. From this study, the star is definitively classified as an evolved δ Sct-type variable with solar metal abundances. This conclusion is also supported by the detected multiperiodic pulsational behaviour and the observed variation of the m1 index over the pulsation cycle. This variation is slightly reversed relative to the V light curve, in very good agreement with the m1 variation expected from the photometric calibrations. Besides the main frequency cd-1 and its first harmonic , a secondary peak is found at cd-1 () with f1 identified as a radial mode and f2 as non-radial. Whereas no significant variations are found in the amplitude of f1 from season to season, the amplitude of f2 changes strongly. Moreover, the main period has remained constant since 1990, within the observational uncertainties. Additional secondary frequencies may also be excited in this variable.
Key words: stars: variables: δ Sct / stars: individual: V2109 Cyg / stars: oscillations / techniques: photometric, spectroscopic
© ESO, 2003