Let a circle passing through (2,0) have its centre at the point (h,k). Let $\left(x_c, y_c\right)$ be the point of intersection of the lines 3x+5y=1 and $(2+c) x+5 c^2 y=1$. If $h=\lim _{c \rightarrow 1} x_c$ and $k=\lim _{c \rightarrow 1} y_c$, then the equation of the circle is :