Given that,
Eccentricity = 0.0086
Suppose, The length of half of the major axis is

We need to calculate the distance from the center to the foci
Using formula of eccentricity


Where, e = eccentricity
a = major axis
c = the distance from the center to the foci
Put the value in to the formula


We need to calculate the perihelion distance of Neptune from the sun
Using formula of distance

Put the value into the formula


Hence, The perihelion distance of Neptune from the sun is 991400000 km.