| Abstract
| - 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 $uvby\beta$ data in the existing catalogues have been used to derive the main physical parameters for the variable. We obtain: $T_{\rm eff}=7490\pm 200$ K, $M_{V}=1\fm02\pm0.2$, $\log g=3.75\pm 0.1$ dex, $M=2.3\pm0.2 M_{odot}$, $R=3.3\pm0.3 R_{odot}$, $\bar{\rho}=0.06\pm0.01 \bar{\rho}_{odot}$, ${\rm age}=1.0\pm 0.1$ Gyr and a distance modulus of ~ $9\fm$12. V1821 Cyg is suggested to be a Population I δ Scuti star with metal-enriched abundances ( ${\rm [M/H]}=0.366$) evolving on its late main sequence stage on the basis of the colour indices and derived properties.
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