  We use long-slit spectra obtained with the 6-m telescope BTA (Russian Academy
of Sciences) to investigate the history of star formation in the peculiar ring
galaxy Arp 10. The radial distributions of quasi-Lick spectral indices are
calculated from the observed spectra and are compared with the model spectra,
the latter are generated using the Starburst99 population synthesis code. Our
model includes an outward propagating density wave which triggers star
formation in the gas disk, and an old stellar disk. The metallicity of both old
and young stellar populations is a function of radius. We show that a mix of
the young and old populations is required to explain the radial distribution of
the spectral indices. The density wave propagates outward with a moderate speed
(of order 40 km/s), and the metallicities of both young and old populations
decrease with the radius. The model indices corresponding to the alpha-elements
require somewhat higher metallicities as compared to the Fe-peak elements. We
acknowledge partial support from grant RFBR 04-02-16518.
