Carbon, nitrogen, oxygen and other elements abundances in the atmospheres of the Delta Scuti pulsating variables. III. V644 Her.

Spectra of the Delta Scuti pulsating variable V644 Her have been investigated using CCD observations with high spectral resolution (0.1 Å) in the regions centered on the lines λ5052 C I; λ6161, 7773 O I; λ8683 N I. The obtained CN abundances lgɛ(C) = 8.35 and lgɛ(N) = 7.82 indicate that in the atmosphere of V644 Her with respect to the Sun there is a small deficiency of these elements: -0.25dex(C) and -0.20dex(N). The oxygen abundance lgɛ(O) = 8.86 in V644 Her is like the Sun. V644 Her has a deficit of Na, Si, S (-0.20dex), and Ca, Sc, Fe (-0.25dex).