SIMBAD references

Stability of both the fundamental and first overtone oscillations of RV Ari was investigated by different methods which led to concordant results. The fundamental period of RV Ari has been decreasing very slowly with a rate of (1/P₀)(dP₀/dt)=-0.6x10^–8yr^–1 while the first overtone period has been increasing a little faster with a rate of (1/P₁)(dP₁/dt)=+0.9x10^–8yr^–1, if we assume linear period changes over the past 65 years. Although the very slow change in the periods is consistent with the evolutionary theories, the fact that the signs of the period changes for the two modes are opposite indicates that the dominating part of the period variation may be the result of non-evolutionary effects. The amplitudes of the fundamental and overtone oscillations have undergone small changes (several mmag) on a time scale of years, and a slight increase in the amplitude of the first overtone pulsation is suspected. An additional frequency at f₂=13.6116c/d is found.