2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/150394The AAVSO lightcurve data of the irregularly pulsating star AC Herculis of the RV Tau class are analysed. The lightcurve is shown to be incompatible with a periodic, or even multiperiodic pulsation, even if allowance is made for evolution. Instead the best explanation is that the irregularly alternating cycles are a manifestation of low dimensional chaos. The lightcurve is found to be generated by a 3 or 4 dimensional dynamics -- 3 or 4 first order ODEs. The (Lyapunov) fractal dimension of the underlying dynamic attractor is computed to be d_L ~ 2.2, smaller than the value of d_L ~ 3.1 found for R Sct.Astronomy & Astrophysics (submitted, June 1997) -- 8 pages. e-mail: kollath@buda.konkoly.hu, buchler@phys.ufl.eduAstrophysicsChaotic Dynamicstext