An Evolutionary Considerations for V228 from 47 Tuc

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We perform evolutionary calculations of binary stars to find progenitors of system with parameters similar to the eclipsing binary system V228. We show that a V228 binary system may be formed starting with an initial binary system which has a low main sequence star as an accretor. The initial parameters for the evolutionary model are as follow: M₁,ᵢ = 0.88 M, M₂,ᵢ = 0.85 M, Pᵢ=1.35 days, f₁=0.05, f₂=4.65 and Z=0.006 ([Fe/H]=--0.67). We also show that the best fitting model implies loss of about 50 per cent of initial total orbital momentum but only 5 per cent of initial total mass. The less massive component have a small helium core of mass 0.12--0.17 M and exchange mass in the nuclear time scale.