8. Given that the number of integer points (points with integer coordinates) on the closed region (including the boundary) enclosed by the circle $x^{2}+y^{2}=8$ is one-fifth of the number of integer points on the closed region (including the boundary) enclosed by the ellipse $\frac{x^{2}}{a^{2}}+\frac{y^{2}}{4}=1$, then the range of the positive real number $a$ is $\qquad$ .
荟䝴 $\quad 22 \leq a21$, 与 $\frac{2 m}{\sqrt{3}} \leq a<[a]+1=21$ contradicts; if $[a]=21$, then $125=5+2 \times 21+4 m \Rightarrow 4 m=78$, which is impossible;
Therefore, $[a]=22, 125=5+2 \times 22+4 m \Rightarrow m=19$, it is not hard to verify
$$
\frac{2 \times 19}{\sqrt{3}}<22 \leq a<[a]+1=23<\frac{2 \times 20}{\sqrt{3}}
$$

Thus $22 \leq a<23$.