Approx one light-day out. The nearest star is 4.2 light-years out.
Doesn't even matter if voyager is heading towards it or not, it's still crazy far away. Voyager is still on our doorstep as far as interstellar distances go.
Light falls off in brightness to the distance squared. So the sun will be 160.7^2 = 25824.5 times fainter for Voyager 2 than it is from Earth. (Since Earth is at 1AU)
The apparent magnitude of the sun from Earth is -26.72. Each step in magnitude is multiplying by 2.512. (2.512^5 = 100, so 5 steps of magnitude is a factor of 100).
log2.512(25824.5) = 11.0295.
11.0295 + -26.72 = -15.6905.
The apparent magnitude of the full moon is only −12.74 (lower is brighter). So for Voyager 2 the sun is still several times brighter than we see the moon. The sun is still many many times brighter than the next brightest star in the sky, Sirius, which has an apparent magnitude of −1.46.
