SIMBAD references

Light curves of classical Cepheids with period longer than 8 days have been Fourier decomposed with the purpose of studying the characteristics of high order Fourier parameters, and to detect possible effects of resonances between pulsation modes other than the well known resonance at P∼10d. The possible effects of two expected resonances have been tentatively identified: P₀/P₁=3/2 at P₀∼24 d and P₀/P₃=3 at P₀∼27d. The identification is not completely certain owing to the poor number of Cepheids. The limitation could be overcome by observing accurately other relatively faint Cepheids in our Galaxy, and several Cepheids in nearby galaxies.