2001A&A...371..233Z

The results of Johnson V time-series CCD photometry of the δ Scuti star V1821 Cygni are presented. Our data set consists of 2431 differential magnitudes and spans the period of July 1999 to September 2000. We detect two best-fit pulsation frequencies representing the light variations of the variable. V1821 Cyg is most likely pulsating in a mixture of radial and nonradial modes. The uvbyβ data in the existing catalogues have been used to derive the main physical parameters for the variable. We obtain: T_eff=7490±200K, M_V=1.02mag±0.2, logg=3.75±0.1dex, M=2.3±0.2M_☉, R=3.3±0.3R_☉, ρ=0.06±0.01ρ_☉, age=1.0±0.1Gyr and a distance modulus of ∼9.12mag. V1821 Cyg is suggested to be a Population I δ Scuti star with metal-enriched abundances ([M/H]=0.366) evolving on its late main sequence stage on the basis of the colour indices and derived properties.